Arctic Sea Ice : Forum

Cryosphere => Antarctica => Topic started by: Laurent on October 27, 2013, 08:30:02 PM

Title: What's new in Antarctica ?
Post by: Laurent on October 27, 2013, 08:30:02 PM
Metallica will play a show in Antartica !
http://todaynewsgazette.com/metallica-antarctica/ (http://todaynewsgazette.com/metallica-antarctica/)
Title: Re: What's new in Antarctica ?
Post by: Laurent on October 27, 2013, 08:33:27 PM
What's the thickness of the ice !
http://www.huffingtonpost.co.uk/2013/06/10/what-does-antarctica-look-like-under-the-ice_n_3414021.html (http://www.huffingtonpost.co.uk/2013/06/10/what-does-antarctica-look-like-under-the-ice_n_3414021.html)
Title: Re: What's new in Antarctica ?
Post by: Laurent on November 01, 2013, 04:56:11 PM
Delegates frustrated as talks to create huge Antarctic marine reserves fail
http://www.theguardian.com/environment/2013/nov/01/antarctic-marine-reserve-talks-fail (http://www.theguardian.com/environment/2013/nov/01/antarctic-marine-reserve-talks-fail)
Title: Re: What's new in Antarctica ?
Post by: Laurent on November 17, 2013, 09:44:31 PM
A question to solve the problem of the milankovitch cycle changing from 40.000 years to 120.000 years.

Where to find 1.5 million yr old ice for the IPICS “Oldest-Ice”
ice core
http://www.clim-past.net/9/2489/2013/cp-9-2489-2013.pdf (http://www.clim-past.net/9/2489/2013/cp-9-2489-2013.pdf)
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 03, 2014, 12:00:59 PM
All Passengers Rescued From Russian Ship Stranded in Antarctic
http://en.ria.ru/world/20140102/186163137/Passenger-Rescue-From-Stranded-Russian-Ship-Delayed-by-Ice.html (http://en.ria.ru/world/20140102/186163137/Passenger-Rescue-From-Stranded-Russian-Ship-Delayed-by-Ice.html)
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 06, 2014, 05:43:41 PM
The story is not finished !
http://www.smh.com.au/environment/icebreaking-rescue-costs-soar-into-the-millions-20140106-30dn0.html (http://www.smh.com.au/environment/icebreaking-rescue-costs-soar-into-the-millions-20140106-30dn0.html)
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 09, 2014, 01:29:03 PM
THE LOST WORLD OF LAKE VOSTOK
http://www.youtube.com/watch?v=4-cRDkuFaQQ#t=10 (http://www.youtube.com/watch?v=4-cRDkuFaQQ#t=10)
Title: News items about Antarctica
Post by: Pmt111500 on January 13, 2014, 03:20:22 AM
http://phys.org/news/2014-01-giant-antarctic-glacier.html (http://phys.org/news/2014-01-giant-antarctic-glacier.html)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on February 13, 2014, 02:00:26 AM
Selected quotes from the linked opinion article are as follow:

" Although the only form of exploration currently allowed in Antarctica is scientific — as the Antarctic Treaty, and the Protocol on Environmental Protection to this treaty, ban any other activities relating to the continent’s mineral resources — this may change in 2048 when the moratorium on exploration and exploitation is up for a review."

"Allocating a large budget to Antarctic research and hosting scientific facilities on the continent are considered suitable ways for a country to signal its presence in this territory, experts say such actions could aid future claims if access to fishing resources is expanded or access to mineral resources is ever granted.
 
“From 2048, only the consultative countries of the Antarctic Treaty will have the right to vote [on any proposed changes to the treaty],” says Marcello Melo da Gama, deputy secretary of Brazil’s Inter-ministerial Commission for the Resources of the Sea (CIRM), the national agency responsible for implementing the country’s Antarctic programme. Twenty-eight countries are consultative parties to the Antarctic Treaty because they were original signatories or now conduct substantial research in Antarctica.
 
“And countries need to have a presence in Antarctica and carry out scientific research there and even have a research base in order to become a consultative party — that is one of the political and strategic reasons to have a base in Antarctica.”
 
As a result, several nations are building or hoping to build new research centres on the continent. This year, both Brazil and China will build research stations."


http://www.trust.org/item/20140212132723-awc5o/?source=hppartner (http://www.trust.org/item/20140212132723-awc5o/?source=hppartner)
Title: Re: What's new in Antarctica ?
Post by: JackTaylor on February 13, 2014, 04:22:40 PM
" Although the only form of exploration currently allowed in Antarctica is scientific — as the Antarctic Treaty, and the Protocol on Environmental Protection to this treaty, ban any other activities relating to the continent’s mineral resources — this may change in 2048 when the moratorium on exploration and exploitation is up for a review."

http://www.trust.org/item/20140212132723-awc5o/?source=hppartner (http://www.trust.org/item/20140212132723-awc5o/?source=hppartner)
THANKS for the reminder on this, (2048 date).

Of note, from the link, is the additional
"tensions are quietly rising regarding sovereignty over the Antarctic continent and the resources on and around it"

Could be an interesting 34 years.
Title: Re: What's new in Antarctica ?
Post by: Laurent on April 12, 2014, 07:22:03 PM
Australia's Antarctic Research Division Faces Cuts

http://news.sciencemag.org/asiapacific/2014/04/australias-antarctic-research-division-faces-cuts (http://news.sciencemag.org/asiapacific/2014/04/australias-antarctic-research-division-faces-cuts)

Title: Re: What's new in Antarctica ?
Post by: crandles on April 13, 2014, 01:22:51 AM
Antarctic sea ice back up to positive anomaly of over 1.5 m Km^2.

2014.2712   1.5424454   5.8333502   4.2909045

Only 4 years have been higher and they are all recent: 2007, 2008, 2010 and 2013.

This puts global anomaly at nearly +1.1 the highest since 2008 reached +1.237 at a very similar time of year:

2014.2712   1.0981402  18.9336891  17.8355484
2008.2767   1.2369218  19.1605587  17.9236374
Title: Re: What's new in Antarctica ?
Post by: Laurent on April 25, 2014, 08:26:27 PM
Quote
Paleoclimate studies suggest that increased global warmth during the Eocene epoch was greatly amplified at high latitudes, a state that climate models cannot fully reproduce. However, proxy estimates of Eocene near-Antarctic sea surface temperatures (SSTs) have produced widely divergent results at similar latitudes, with SSTs above 20 °C in the southwest Pacific contrasting with SSTs between 5 and 15 °C in the South Atlantic.

http://www.pnas.org/content/early/2014/04/16/1321441111.abstract?sid=416fb7a8-dbf3-43d0-9dba-8b4bbcf0c1a0 (http://www.pnas.org/content/early/2014/04/16/1321441111.abstract?sid=416fb7a8-dbf3-43d0-9dba-8b4bbcf0c1a0)
Title: Re: What's new in Antarctica ?
Post by: Stephen on May 05, 2014, 06:55:07 AM
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2226.html (http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2226.html)

New nature article suggest instability in Wilkes basin

Quote from Matthias Mengel of the Potsdam Institute for Climate Impact Research
"The Wilkes is vulnerable because it is held in place by a small rim of ice, resting on bedrock below sea level by the coast of the frozen continent. That ice plug might melt away in coming centuries if ocean waters warm up."
Title: Re: What's new in Antarctica ?
Post by: Laurent on June 17, 2014, 01:02:28 AM
'Weedy thing' thrives as Antarctic shores warm
http://www.bbc.com/news/science-environment-27831958 (http://www.bbc.com/news/science-environment-27831958)
Title: Re: What's new in Antarctica ?
Post by: Laurent on June 30, 2014, 04:29:57 PM
Emperor Penguins are now endangered, warn biologists
http://www.telegraph.co.uk/earth/environment/climatechange/10933964/Emperor-Penguins-are-now-endangered-warn-biologists.html (http://www.telegraph.co.uk/earth/environment/climatechange/10933964/Emperor-Penguins-are-now-endangered-warn-biologists.html)

Melting ice puts emperor penguins on a slippery slope
http://www.newscientist.com/article/dn25812-melting-ice-puts-emperor-penguins-on-a-slippery-slope.html?cmpid=RSS (http://www.newscientist.com/article/dn25812-melting-ice-puts-emperor-penguins-on-a-slippery-slope.html?cmpid=RSS)|NSNS|2012-GLOBAL|environment#.U7FxilFJzlc
Title: Re: What's new in Antarctica ?
Post by: DavidR on July 08, 2014, 01:16:49 AM
Australian Scientists have identified a mechanism that  will accelerate the loss of Antarctic ice over the next Century.
"Warm water is likely to increasingly displace cold water around the Antarctic coastline, prompting accelerated ice melt and more sea level rise, according to new Australian research. "
http://www.abc.net.au/news/2014-07-07/giant-antarctic-ice-shelves-could-melt-faster-than-expected/5579678 (http://www.abc.net.au/news/2014-07-07/giant-antarctic-ice-shelves-could-melt-faster-than-expected/5579678)
Title: Re: What's new in Antarctica ?
Post by: wili on July 08, 2014, 03:00:45 PM
So when you put all the accelerating factors toward increased slr that we have been hearing about for the past few months together, where does that put us?

Before all these studies, iirc, the consensus estimate was about one meter by the end of the century. So where are we now? A meter by mid-century? In thirty years? Twenty?...Two meters by century's end? Three? Four?

Has anyone put all these together to come up with new estimates with probabilities for each?

ASLR, are you out there?
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 08, 2014, 06:59:37 PM
wili,

First, no new published papers have yet been issued putting together all of these different recent accelerating factors, and no new expert survey's have been published reflecting any specific changes in SLR expert thought on this matter.  NOAA already has a curve showing 2m of SLR by 2100 for their "high range" value.

Second, as for myself, I have had essentially no change in my position on projected SLR by 2100 in my over 2,500 posts, so if you go to the "Philosophical" thread you can see my projections posted there from over 1.5 years ago, where I already assumed all of the findings just newly being published now.

Third, I doubt that policy makers will change any guidance on this matter for another several years (maybe 10-years), as they can still hide behind uncertainty until the glacier models become much more sophisticated than they current are.

Best,
ASLR
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 08, 2014, 07:14:29 PM
wili,

I guess that I should add that given the limitations of the glacial models, Eric Rignot is currently working on a Big Data approach to estimate coming SLR estimates; however, I have already seen articles by denialists saying that Big Data approaches are biased and cannot be relied upon by policy makers entrusted with the public purse.  Therefore, it appears that there will not be a global consensus on eustatic SLR anytime soon; which will leave various local authorities using different projections based on their risk tolerance.

Best,
ASLR

Title: Re: What's new in Antarctica ?
Post by: wili on July 08, 2014, 08:18:44 PM
Thanks, ASLR. I wonder if a statistical number cruncher like tamino might take this on.

So just to be clear (and so I don't have to read again through all 2500+ of your wonderful posts, educational as that would be  :) ), you are sticking with Hansen's projection of 5 meters by 2100?
Title: Re: What's new in Antarctica ?
Post by: steve s on July 08, 2014, 08:37:35 PM
Two meters by 2100 is roughly an inch or 2.5 cm per year on average. If, as most of us on this thread seem to think, this proves low estimate, policy makers will soon be forced to accept SLR as important. Actually, much earlier as Rignot has set the stage for the rate of change of the rate of change entering the public awareness as a justification.

("Let the cry ring out to all who will listen: To arms, to arms, for the Thwaites is coming.")

A Pyrrhic victory, no matter how soon the recognition comes, but sooner is better.

Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 09, 2014, 12:21:11 AM
wili,

As I live in California, and I am convinced that the world will more or less stay on a BAU pathway through at least 2050, I have provided the attached projections for RSLR in California for RCP 8.5 forcing scenario.  While these are close to Hansen's projections they are different on a number of counts, and a the third image shows an assumed grounding line retreat comparable to that stated by Rignot to be the onset of the rapid collapse phase for the ASE marine glaciers (the "WAIS Collapse" thread contains may other details):

(edit: note that these PDFs include all sources of RSLR and include a 1.4 multiplier on eustatic SLR contribution from the WAIS for the RSLR in California)

Best,
ASLR
Title: Re: What's new in Antarctica ?
Post by: solartim27 on July 18, 2014, 12:46:10 AM
The CT chart shows a crash in the AASI anomaly of over 1M km2.  The graphs from the previous 2 years also show similar pauses in growth, but nothing that dramatic.  Anyone have any theories?
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png (http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png)
Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on July 18, 2014, 01:36:43 PM
Cryosat2 data for Antarctica now out;

http://onlinelibrary.wiley.com/doi/10.1002/2014GL060111/abstract (http://onlinelibrary.wiley.com/doi/10.1002/2014GL060111/abstract)

seems we saw west antarctica step up it's losses from 2005 to 2010 by 31%???
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 18, 2014, 10:56:19 PM
solartim 27,

Per the attached link, the AAO has been largely positive since about June 7 2014, so maybe this has changed the wind patterns sufficiently to slow the rate of Antarctic sea ice formation (particularly in the Weddell, and Ross, Seas):

http://ossfoundation.us/projects/environment/global-warming/antarctic-oscillation-aao (http://ossfoundation.us/projects/environment/global-warming/antarctic-oscillation-aao)

Best,
ASLR
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 19, 2014, 03:37:08 PM
Sleepy,

Thanks for the great legwork on this matter.  While the AAO still might be one contributing factor to the behavior you indicate, I also note that the Indian Ocean Dipole (IOD) went negative in this general timeframe (which could encourage the export of warm winds from Australia southward; see attached the first attached image of the recent IOD history plot through July 13 2014, and the second attached figure of the IOD forecast, both by the BoM):
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 23, 2014, 05:01:56 AM
Sleepy (and AlanW),

Thanks again.

Best,
ASLR
Title: Re: What's new in Antarctica ?
Post by: Laurent on August 10, 2014, 04:33:13 PM
What to do when the power goes out in Antarctica
http://www.newscientist.com/article/dn26019-what-to-do-when-the-power-goes-out-in-antarctica.html?cmpid=RSS (http://www.newscientist.com/article/dn26019-what-to-do-when-the-power-goes-out-in-antarctica.html?cmpid=RSS)|NSNS|2012-GLOBAL|environment#.U-d-bZjodeQ
Title: Re: What's new in Antarctica ?
Post by: Laurent on August 21, 2014, 09:46:43 AM
Antarctic hides extreme ecosystem
http://www.bbc.com/news/science-environment-28853387 (http://www.bbc.com/news/science-environment-28853387)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on August 31, 2014, 05:37:10 PM
Not really 'new', but thought it would be of interest.
http://www.latimes.com/science/la-sci-antarctic-sea-ice-20140830-story.html#page=1 (http://www.latimes.com/science/la-sci-antarctic-sea-ice-20140830-story.html#page=1)
Title: Re: What's new in Antarctica ?
Post by: Laurent on September 13, 2014, 09:21:33 AM
26. August 2014: Greenhouse Gases in the Southern Ocean: First Evidence of Active Methane Emission at the Antarctic Seafloor
http://www.awi.de/en/news/press_releases/detail/item/greenhouse_gases_in_the_southern_ocean_first_evidence_of_active_methane_emission_at_the_antarctic_s/?tx_list_pi1 (http://www.awi.de/en/news/press_releases/detail/item/greenhouse_gases_in_the_southern_ocean_first_evidence_of_active_methane_emission_at_the_antarctic_s/?tx_list_pi1)[mode]=6&cHash=ac9056f0576b288b18d7c3989cf78865
Title: Re: What's new in Antarctica ?
Post by: Laurent on September 18, 2014, 07:04:36 PM
33 Amazing Species -- And a Chance to Save Them
http://www.huffingtonpost.com/john-hocevar/33-amazing-species-and-a-_b_5823668.html?utm_hp_ref=green&ir=Green (http://www.huffingtonpost.com/john-hocevar/33-amazing-species-and-a-_b_5823668.html?utm_hp_ref=green&ir=Green)

http://antarcticocean.org (http://antarcticocean.org)
Title: Re: What's new in Antarctica ?
Post by: Laurent on September 26, 2014, 12:50:12 AM
http://www.whiteicecycle.com/ (http://www.whiteicecycle.com/)
Title: Re: What's new in Antarctica ?
Post by: Laurent on October 31, 2014, 09:55:31 PM
China And Russia Block International Plan To Create Antarctic Ocean Sanctuary
http://www.huffingtonpost.com/2014/10/31/plan-antarctic-ocean-sanctuary_n_6082986.html?utm_hp_ref=green&ir=Green (http://www.huffingtonpost.com/2014/10/31/plan-antarctic-ocean-sanctuary_n_6082986.html?utm_hp_ref=green&ir=Green)
Title: Re: What's new in Antarctica ?
Post by: Laurent on November 29, 2014, 12:55:12 PM
Researchers stock up on way to Antarctic
http://www.ecns.cn/2014/11-19/143291.shtml (http://www.ecns.cn/2014/11-19/143291.shtml)

Quote
China's 31st Antarctic expedition group is set to call in at Hobart, Australia, to pick up supplies before continuing its journey aboard the Xuelong, or Snow Dragon, the country's only research icebreaker.
Title: Re: What's new in Antarctica ?
Post by: Laurent on December 02, 2014, 01:35:29 PM
A complete breeding failure in an Adélie penguin colony correlates with unusual and extreme environmental events
http://www.ecography.org/accepted-article/complete-breeding-failure-adelie-penguin-colony-correlates-unusual-and-extreme (http://www.ecography.org/accepted-article/complete-breeding-failure-adelie-penguin-colony-correlates-unusual-and-extreme)
Title: Re: What's new in Antarctica ?
Post by: Laurent on December 20, 2014, 10:33:15 AM
Antarctic photo science archive unlocked
http://www.bbc.com/news/science-environment-30471542 (http://www.bbc.com/news/science-environment-30471542)
Title: Re: What's new in Antarctica ?
Post by: Sigmetnow on December 29, 2014, 03:21:37 PM
What happened to the tourist/research ship that got stuck in Antarctic ice last year.  Some of their findings on sea flow and marine life were quite surprising.
Article and 20-min video.
http://www.theguardian.com/science/2014/dec/25/rescued-scientists-warning-from-antarctica (http://www.theguardian.com/science/2014/dec/25/rescued-scientists-warning-from-antarctica)
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 10, 2015, 10:58:38 AM
Extreme Ice Survey: Farewell to the Antarctic Peninsula
http://www.huffingtonpost.com/lindblad-expeditions/extreme-ice-survey-farewe_b_6439318.html?utm_hp_ref=green&ir=Green (http://www.huffingtonpost.com/lindblad-expeditions/extreme-ice-survey-farewe_b_6439318.html?utm_hp_ref=green&ir=Green)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 10, 2015, 05:37:48 PM
While I have seen some minor criticisms that Richard Alley can be too caution, I disagree with such criticisms, given the state of our current decision making system/process.  Therefore, I would like to congratulate Richard Alley on winning the 2015 BBVA Foundation Frontiers of Knowledge Award in the Climate Change category, for his pioneering work on abrupt climate change.

http://www.prnewswire.com/news-releases/the-bbva-foundation-frontiers-of-knowledge-award-goes-to-richard-alley-the-interpreter-of-ice-who-uncovered-the-evidence-of-sudden-climate-changes-300018445.html (http://www.prnewswire.com/news-releases/the-bbva-foundation-frontiers-of-knowledge-award-goes-to-richard-alley-the-interpreter-of-ice-who-uncovered-the-evidence-of-sudden-climate-changes-300018445.html)

Extract: "The seventh annual BBVA Foundation Frontiers of Knowledge Award in the Climate Change category goes to U.S. glaciologist Richard Alley for his "pioneering research" into the "mechanics of ice and its implications for abrupt climate change," in the words of the jury's citation."

Also see:
http://www.fbbva.es/TLFU/tlfu/ing/microsites/premios/fronteras/index.jsp (http://www.fbbva.es/TLFU/tlfu/ing/microsites/premios/fronteras/index.jsp)
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 12, 2015, 10:15:40 AM
Should tourists be banned from Antarctica?
http://www.bbc.com/news/magazine-30709924 (http://www.bbc.com/news/magazine-30709924)
Title: Re: What's new in Antarctica ?
Post by: Yuha on January 18, 2015, 03:48:16 PM
Did Meteorite Carve Icy Antarctic Crater?
http://www.livescience.com/49398-antarctica-ice-meteorite-crater-found.html (http://www.livescience.com/49398-antarctica-ice-meteorite-crater-found.html)
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 21, 2015, 05:32:03 PM
Antarctic toothfish poaching ships shrug off New Zealand navy
http://www.theguardian.com/environment/2015/jan/21/antarctic-toothfish-poaching-ships-shrug-off-new-zealand-navy (http://www.theguardian.com/environment/2015/jan/21/antarctic-toothfish-poaching-ships-shrug-off-new-zealand-navy)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 24, 2015, 02:20:36 AM
Huh
http://www.scientificamerican.com/article/discovery-fish-live-beneath-antarctica1/ (http://www.scientificamerican.com/article/discovery-fish-live-beneath-antarctica1/)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 24, 2015, 05:33:49 PM
Did Meteorite Carve Icy Antarctic Crater?
http://www.livescience.com/49398-antarctica-ice-meteorite-crater-found.html (http://www.livescience.com/49398-antarctica-ice-meteorite-crater-found.html)

The nearly 2 miles (3 kilometers) wide ring of sunken ice on the Roi Baudoin Ice Shelf in East Antarctica is most likely not an meteor impact crater but instead is actually an ice doline formed by water draining out of a sub-ice-surface lake (see linked article below).

http://www.nbcnews.com/science/weird-science/scientists-shoot-down-meteorite-theory-antarctica-crater-mystery-n292326 (http://www.nbcnews.com/science/weird-science/scientists-shoot-down-meteorite-theory-antarctica-crater-mystery-n292326)
Title: Re: What's new in Antarctica ?
Post by: Laurent on February 03, 2015, 08:43:25 PM
Lewis Pugh to undertake 'world's most dangerous swim' in Antarctic for campaign to make Ross Sea a protected area
http://www.independent.co.uk/environment/lewis-pugh-to-undertake-worlds-most-dangerous-swim-in-antarctic-for-campaign-to-make-ross-sea-a-protected-area-10021130.html (http://www.independent.co.uk/environment/lewis-pugh-to-undertake-worlds-most-dangerous-swim-in-antarctic-for-campaign-to-make-ross-sea-a-protected-area-10021130.html)
Title: Re: What's new in Antarctica ?
Post by: Laurent on February 04, 2015, 10:16:43 AM
Subglacial Lake Vostok cracked for a second time
http://www.newscientist.com/article/dn26907-subglacial-lake-vostok-cracked-for-a-second-time.html?cmpid=RSS (http://www.newscientist.com/article/dn26907-subglacial-lake-vostok-cracked-for-a-second-time.html?cmpid=RSS)|NSNS|2012-GLOBAL|environment#.VNHhO2N3_z8
Title: Re: What's new in Antarctica ?
Post by: johnm33 on February 04, 2015, 11:31:42 AM
Anyone have a sub to N.S. to access this http://www.newscientist.com/article/mg22530060.400-thaw-point-why-is-antarcticas-sea-ice-still-growing.html (http://www.newscientist.com/article/mg22530060.400-thaw-point-why-is-antarcticas-sea-ice-still-growing.html)
Title: Re: What's new in Antarctica ?
Post by: Jim Hunt on February 04, 2015, 01:14:17 PM
Anyone have a sub to N.S. to access this?

Yes - What would you like to know?
Title: Re: What's new in Antarctica ?
Post by: johnm33 on February 04, 2015, 03:29:41 PM
 JimHunt "Yes - What would you like to know?" Well breifly his veiw, I checked out the BAS site and couldn't find anything there, the press part of it seemed dysfunctional, tried a wider search and had no luck.
Sands back at Porthleven btw.
johnm
Title: Re: What's new in Antarctica ?
Post by: Jim Hunt on February 07, 2015, 07:11:27 PM
Just posted by NASA - A chip off the King Baudouin Ice Shelf:

http://earthobservatory.nasa.gov/IOTD/view.php?id=85235 (http://earthobservatory.nasa.gov/IOTD/view.php?id=85235)

Quote
While large icebergs calve regularly from fast-flowing ice shelves in West Antarctica, the coast of cooler, drier East Antarctica tends to be less active. That made it a mild surprise when a 70-square-kilometer chunk of ice broke off from the King Baudouin Ice Shelf in January 2015. The last time that part of King Baudouin calved such a large iceberg was in the 1960s.

Also visible on WorldView on February 3rd, having already moved a fair distance: http://1.usa.gov/1EOlIwN (http://1.usa.gov/1EOlIwN)

Title: Re: What's new in Antarctica ?
Post by: Jim Hunt on February 07, 2015, 08:23:29 PM
Well breifly his veiw, I checked out the BAS site and couldn't find anything there.

Sorry John. I missed this. Too busy battling the forces of darkness (http://greatwhitecon.info/2015/02/a-letter-to-the-editor-of-the-mail-on-sunday/)! How about this bit?

Quote
There is no longer an autumn lockstep between wind and ice. The most glaring clash is in the Bellingshausen Sea. There, the autumn winds have become stronger. They blow from the north, which must be shoving more ice in towards the coast, keeping it from spreading, as well as carrying warmer air from temperate regions. Indeed, the overall area of autumn sea ice here has declined, which would seem to fit with that idea. But if the stronger winds were the key factor affecting ice growth, the ice should be growing more slowly. In fact, during autumn it is growing faster than it did a few decades ago. "That destroys my earlier work," Holland says.

He now thinks that to understand these changes in sea ice, we need to focus on what's happening in the spring. In the Bellingshausen Sea, ice is now retreating earlier in the springtime, letting the ocean absorb more solar heat. That warming should delay the regrowth of ice – accounting for the decline in ice area in autumn. But when the ice does grow back, it does so quickly, because now the ocean is open to the air, it rapidly loses its heat again.

In other words, sea ice has a tendency to bounce back from big spring losses. This was first noted in Antarctica by Stammerjohn, in a 2008 study (http://dx.doi.org/10.1029/2007JC004269) that looked at how ice is changing region by region and season by season.

or this?

Quote
Dirk Notz, however, is not convinced that Holland is right to focus on whether sea ice is melting or forming faster or more slowly than it used to. "He is looking at a change in a rate of change," he says. "I do not think it's a measure that is important."

So Notz's team thinks that the wind explanation still holds. The reason most climate models have been projecting sea ice losses, they argue in a study (http://onlinelibrary.wiley.com/doi/10.1002/2014GL061659/abstract) published in December, is that they are too coarse-grained. They miss details of Antarctic topography that deflect winds northwards and spread out sea ice, allowing more ice to form.

Returning to a still somewhat chilly SW England.

Quote
Sands back at Porthleven btw.

I'm glad to hear it!
Title: Re: What's new in Antarctica ?
Post by: Laurent on February 12, 2015, 10:08:29 AM
Fishing vessel trapped in Antarctic ice; U.S. Coast Guard on rescue mission
http://www.latimes.com/nation/la-na-coast-guard-20150211-story.html (http://www.latimes.com/nation/la-na-coast-guard-20150211-story.html)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on February 12, 2015, 09:51:40 PM
I don't know how new this is, but I found that Polar View also has antarctic Sentinel images available, though i find the coverage lacking
http://www.polarview.aq/antarctic (http://www.polarview.aq/antarctic)

There is also another site that looks like it is new from University of Alaska, Fairbanks.  I don't know how much coverage it will give to the Antarctic.
https://www.asf.alaska.edu/ (https://www.asf.alaska.edu/)
Title: Re: What's new in Antarctica ?
Post by: wili on February 15, 2015, 06:16:16 PM
Sorry if this was already covered somewhere, but it seems like kind of a big deal:

http://www.the-cryosphere-discuss.net/9/861/2015/tcd-9-861-2015.html (http://www.the-cryosphere-discuss.net/9/861/2015/tcd-9-861-2015.html)

Newly developing rift in Larsen C Ice Shelf presents significant risk to stability


Quote
An established rift in the Larsen C Ice Shelf, formerly constrained by a suture zone containing marine ice, grew rapidly during 2014 and is likely in the near future to generate the largest calving event since the 1980s and result in a new minimum area for the ice shelf. Here we investigate the recent development of the rift, quantify the projected calving event and, using a numerical model, assess its likely impact on ice shelf stability. We find that the ice front is at risk of becoming unstable when the anticipated calving event occurs.

More, and image, here: http://www.desdemonadespair.net/2015/02/image-of-day-satellite-view-of-rift.html (http://www.desdemonadespair.net/2015/02/image-of-day-satellite-view-of-rift.html)

ETA: Ah, I see ASLR (of course) has a couple posts on this with many good images on the neighboring thread "Discussion of Antarctic Peninsula"
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on February 17, 2015, 02:34:15 AM
The linked article states that: "Penguins can taste only sour and salty food, scientists have discovered.  A genetic study suggests the flightless birds lost three of the five basic tastes long ago in evolution."


http://www.bbc.com/news/science-environment-31490623 (http://www.bbc.com/news/science-environment-31490623)
Title: Re: What's new in Antarctica ?
Post by: Laurent on February 20, 2015, 02:03:34 PM
You want a job in Antartica ?
http://www.ukaht.org/about-us/jobs (http://www.ukaht.org/about-us/jobs)
Title: Re: What's new in Antarctica ?
Post by: Chuck Yokota on March 16, 2015, 06:31:03 PM
East Antarctica Melting Could be Explained by Oceanic Gateways

http://www.utexas.edu/news/2015/03/16/east-antarctica-melting-could-be-explained-by-oceanic-gateways/ (http://www.utexas.edu/news/2015/03/16/east-antarctica-melting-could-be-explained-by-oceanic-gateways/)

Quote
AUSTIN,Texas — Researchers at The University of Texas at Austin’s Institute for Geophysics (UTIG) in the Jackson School of Geosciences have discovered two seafloor gateways that could allow warm ocean water to reach the base of Totten Glacier, East Antarctica’s largest and most rapidly thinning glacier. The discovery, reported in the March 16 edition of the journal Nature Geoscience, probably explains the glacier’s extreme thinning and raises concerns about how it will affect sea level rise.

Totten Glacier is East Antarctica’s largest outlet of ice to the ocean and has been thinning rapidly for many years. Although deep, warm water has been observed seaward of the glacier, until now there was no evidence that it could compromise coastal ice. The result is of global importance because the ice flowing through Totten Glacier alone is sufficient to raise global sea level by at least 11 feet, equivalent to the contribution of the West Antarctic Ice Sheet if it were to completely collapse.

“We now know there are avenues for the warmest waters in East Antarctica to access the most sensitive areas of Totten Glacier,” said lead author Jamin Greenbaum, a UTIG Ph.D. candidate.

The ice loss to the ocean may soon be irreversible unless atmospheric and oceanic conditions change so that snowfall outpaces coastal melting. The potential for irreversible ice loss is due to the broadly deepening shape of Totten Glacier’s catchment, the large collection of ice and snow that flows from a deep interior basin to the coastline.
Title: Re: What's new in Antarctica ?
Post by: crandles on March 27, 2015, 03:06:26 AM
Volume loss from Antarctic ice shelves is accelerating

Quote
The floating ice shelves surrounding the Antarctic Ice Sheet restrain the grounded ice-sheet flow. Thinning of an ice shelf reduces this effect, leading to an increase in ice discharge to the ocean. Using eighteen years of continuous satellite radar altimeter observations we have computed decadal-scale changes in ice-shelf thickness around the Antarctic continent. Overall, average ice-shelf volume change accelerated from negligible loss at 25 ± 64 km3 per year for 1994-2003 to rapid loss of 310 ± 74 km3 per year for 2003-2012. West Antarctic losses increased by 70% in the last decade, and earlier volume gain by East Antarctic ice shelves ceased. In the Amundsen and Bellingshausen regions, some ice shelves have lost up to 18% of their thickness in less than two decades.

http://www.sciencemag.org/content/early/2015/03/25/science.aaa0940 (http://www.sciencemag.org/content/early/2015/03/25/science.aaa0940)

http://www.bbc.co.uk/news/science-environment-31965454 (http://www.bbc.co.uk/news/science-environment-31965454)
Title: Re: What's new in Antarctica ?
Post by: DavidR on March 27, 2015, 09:17:54 AM
New research shows Antarctic ice shelves thinned rapidly in the last decade and much faster than scientists had thought.
This may just  be another take on the articles report by  crandles.
http://www.abc.net.au/news/2015-03-27/antarctic-ice-shelves-thinning-more-rapidly-scientists-thought/6354530 (http://www.abc.net.au/news/2015-03-27/antarctic-ice-shelves-thinning-more-rapidly-scientists-thought/6354530)
Title: Re: What's new in Antarctica ?
Post by: Clare on March 29, 2015, 07:34:57 AM
Tim Naish -Director of the Antarctic Research Centre at Victoria University of Wellington. He will discuss the new findings this week on the decrease in volume of Antarctic ice on Radio NZ.

http://www.radionz.co.nz/national/programmes/saturday/audio/20172781/tim-naish-antarctic-ice-shelves (http://www.radionz.co.nz/national/programmes/saturday/audio/20172781/tim-naish-antarctic-ice-shelves)

He always explains things v clearly, this is a summary of recent research for a general audience, the interviewer herself has been to Antarctica in past.
Pic =Travelling out to Andrill drill site on Ross Ice Shelf in 2006 with Tim
Title: Re: What's new in Antarctica ?
Post by: Sleepy on March 29, 2015, 09:06:23 AM
Thanks Clare, that was indeed a very nice interview.
No big news for a lot of people reading here, but I think it's very usable in communicating the scientific view to those who never read.
I'll add the mp3 version here.
Title: Re: What's new in Antarctica ?
Post by: Sigmetnow on March 29, 2015, 07:18:11 PM
Quote
The warmest temperature ever recorded on the continent of Antarctica may have occurred on Tuesday, March 24, 2015, when the mercury shot up to 63.5°F (17.5°C) at Argentina's Esperanza Base on the northern tip of the Antarctic Peninsula. According to weather records researcher Maximiliano Herrera, the previous hottest temperature recorded in Antarctica was 63.3°F (17.4°C) set just one day previously at Argentina's Marambio Base, on a small islet just off the coast of the Antarctic Peninsula. Prior to this week's remarkable heat wave, the hottest known temperature in Antarctica was the 62.8°F (17.1°C) recorded at Esperanza Base on April 24, 1961. (The World Meteorological Organization—WMO—has not yet certified that this week's temperatures are all-time weather records for Antarctica, though the Argentinian weather service has verified that the temperatures measured at Esperanza Base and Marambio Base were the highest ever measured at each site.) A new all-time temperature record for an entire continent is a rare event, and Weather Underground's weather historian, Christopher C. Burt, has full details in his latest post.
Dr. Jeff Masters:
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2944&cm_ven=tw-jm (http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2944&cm_ven=tw-jm)

Christopher C. Burt:
http://www.wunderground.com/blog/weatherhistorian/comment.html?entrynum=323# (http://www.wunderground.com/blog/weatherhistorian/comment.html?entrynum=323#)

WaPo:
http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2015/03/27/antarctica-may-have-set-highest-temperature-ever-recorded-tuesday/ (http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2015/03/27/antarctica-may-have-set-highest-temperature-ever-recorded-tuesday/)

Title: Re: What's new in Antarctica ?
Post by: Laurent on April 01, 2015, 10:07:51 AM
Antarctica records unprecedented high temperatures in two new readings
http://www.theguardian.com/environment/2015/mar/31/potential-record-high-temperature-in-antarctica-alarms-scientists (http://www.theguardian.com/environment/2015/mar/31/potential-record-high-temperature-in-antarctica-alarms-scientists)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on May 06, 2015, 01:26:35 AM
The linked NY Times article discusses China's power-play in Antarctica:

http://www.nytimes.com/2015/05/04/world/asia/china-pursuing-strategic-interests-builds-presence-in-antarctica.html?_r=0 (http://www.nytimes.com/2015/05/04/world/asia/china-pursuing-strategic-interests-builds-presence-in-antarctica.html?_r=0)
Title: Re: What's new in Antarctica ?
Post by: Laurent on May 08, 2015, 09:54:45 AM
Antarctic creatures found on Niwa trip
http://www.stuff.co.nz/environment/68378627/antarctic-creatures-found-on-niwa-trip (http://www.stuff.co.nz/environment/68378627/antarctic-creatures-found-on-niwa-trip)
Title: Re: What's new in Antarctica ?
Post by: Laurent on May 11, 2015, 03:42:30 PM
Ice loss in west Antarctica is speeding up
http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/may/11/ice-loss-in-west-antarctica-is-speeding-up (http://www.theguardian.com/environment/climate-consensus-97-per-cent/2015/may/11/ice-loss-in-west-antarctica-is-speeding-up)
Title: Re: What's new in Antarctica ?
Post by: johnm33 on May 24, 2015, 01:06:28 AM
Sorry if this has been linked elsewhere http://phys.org/news/2015-05-sudden-onset-ice-loss-antarctica.html (http://phys.org/news/2015-05-sudden-onset-ice-loss-antarctica.html)
ftp://ftp-projects.zmaw.de/seaice/AMSR2/Ant_latest_yesterday_AMSR2_3.125km.png (http://ftp://ftp-projects.zmaw.de/seaice/AMSR2/Ant_latest_yesterday_AMSR2_3.125km.png)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on June 06, 2015, 09:20:51 PM
Less ice means more seaweed
http://earthsky.org/earth/seaweed-colonizing-ice-free-parts-of-antarctica (http://earthsky.org/earth/seaweed-colonizing-ice-free-parts-of-antarctica)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on June 06, 2015, 11:46:42 PM
Deep ice core in Antarctica used to compare to conditions in Greenland:
http://www.realclimate.org/index.php/archives/2015/04/how-long-does-it-take-antarctica/ (http://www.realclimate.org/index.php/archives/2015/04/how-long-does-it-take-antarctica/)
Title: Re: What's new in Antarctica ?
Post by: Clare on June 28, 2015, 11:52:55 AM
Good long detailed Q&A with Nancy Bertler:
"Antarctica - our big icy threat"
http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11472481 (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11472481)

& you can see her 'on the job' in this clip from Thin Ice:
https://vimeo.com/43012949 (ftp://vimeo.com/43012949)

(sorry but I cant fathom how to embed this as a video. :-(  )

http://thiniceclimate.org/blog/details/2013/digging-a-snow-pit-in-antarctica-nancy-bertler (http://thiniceclimate.org/blog/details/2013/digging-a-snow-pit-in-antarctica-nancy-bertler)

Clare
Title: Re: What's new in Antarctica ?
Post by: Jim Hunt on July 03, 2015, 09:52:06 AM
(sorry but I cant fathom how to embed this as a video. :-(  )

The forum software doesn't seem to understand Vimeo. Is there a YouTube version of the same video?
Title: Re: What's new in Antarctica ?
Post by: johnm33 on July 15, 2015, 11:19:38 AM
Large version ftp://ftp-projects.zmaw.de/seaice/AMSR2/Ant_20150702_res3.125_LARGE.png from ftp://ftp-projects.zmaw.de/seaice/AMSR2/
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 15, 2015, 05:27:35 PM
The linked article discusses fifty-million-year-old worm sperm cells found frozen in Antarctic ice:

http://www.huffingtonpost.com/entry/worlds-oldest-sperm-discovered-in-antarctica_55a65d9ce4b0c5f0322bcb6f (http://www.huffingtonpost.com/entry/worlds-oldest-sperm-discovered-in-antarctica_55a65d9ce4b0c5f0322bcb6f)

Extract: "Fifty-million-year-old sperm cells from a worm have been found in Antarctica, National Geographic reports. The fossilized sperm, which was preserved in the walls of an egg case, is the “oldest fossil animal sperm yet known,” according to a paper published Wednesday in the journal Biology Letters by researchers at the Swedish Museum of Natural History in Stockholm."
Title: Re: What's new in Antarctica ?
Post by: Lennart van der Linde on October 06, 2015, 09:14:41 AM
Zwally et al 2015 on snowfall in the interior of Antarctica offsetting ice loss at the edges, for now:
http://www.nature.com/news/gains-in-antarctic-ice-might-offset-losses-1.18486?WT.mc_id=TWT_NatureNews (http://www.nature.com/news/gains-in-antarctic-ice-might-offset-losses-1.18486?WT.mc_id=TWT_NatureNews)

If true, this would imply more ice loss from GIS or small glaciers, and/or more thermal expansion, and/or less overall SLR, for now.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on October 06, 2015, 05:29:42 PM
Zwally et al 2015 on snowfall in the interior of Antarctica offsetting ice loss at the edges, for now:
http://www.nature.com/news/gains-in-antarctic-ice-might-offset-losses-1.18486?WT.mc_id=TWT_NatureNews (http://www.nature.com/news/gains-in-antarctic-ice-might-offset-losses-1.18486?WT.mc_id=TWT_NatureNews)

If true, this would imply more ice loss from GIS or small glaciers, and/or more thermal expansion, and/or less overall SLR, for now.

The following extract is from the author & indicates that his findings do not mean that we do not need to worry about AIS contribution to SLR, only that there is still uncertainty about timing & rate of contribution:

Extract: "The findings do not mean that Antarctica is not in trouble, Zwally notes. “I know some of the climate deniers will jump on this, and say this means we don’t have to worry as much as some people have been making out,” he says. “It should not take away from the concern about climate warming.” As global temperatures rise, Antarctica is expected to contribute more to sea-level rise, though when exactly that effect will kick in, and to what extent, remains unclear."
Title: Re: What's new in Antarctica ?
Post by: A-Team on October 07, 2015, 01:28:55 PM
The Zwally paper has been accepted but the stodgy Journal of Glaciology does not provide an online copy and there's no telling when it will appear, firewalled, in an issue. Reviewer comments are kept secret permanently.

A copy could like be obtained by emailing Zwally at his NASA profile page. His older papers are available for download at https://www.researchgate.net/profile/H_Zwally2/publications (https://www.researchgate.net/profile/H_Zwally2/publications)

Mass gains of the Antarctic ice sheet exceed losses
H. Jay Zwally, Jun Li, John W. Robbins, Jack L. Saba, Donghui Yi, Anita C. Brenner
accepted Journal of Glaciology #15J071

Antarctica mass balance has gone back and forth for years by ±75 Gt, Grace gravity vs laser altimetry. The latter has serious issues with firn modelling. Zwally attributes the difference to how GRACE researchers account for changes in the height of the bedrock (isostatic rebound). We have not yet heard from the other side.
Quote
Glacial ice forms as snow compresses under its own weight. In this case, the gain in ice mass in parts of Antarctica has not come from snowfall in the modern era, but from heavier snows that fell about 10,000 years ago, says Zwally. That snow became ice and started to flow slowly towards the sea — but so slowly that the ice began to thicken.
In my view, the mass gain approach makes sense until it doesn't. The issue today is really warm ocean waters lapping at the underside of vast ice shelves. As these come to destabilize grounded ice up-glacier, any slight excess of snowfall over ablation will fall through the floor quantitatively speaking.

The Swally paper is also saying Greenland mass balance has been figured quite wrong, ie it is contributing more to sea level rise than thought. I'm recalling 1/3 which would have to go to 2/3 since thermal expansion is not likely to be misfigured. Yet Greenland, being so much smaller and experimentally accessible than Antarctica, is better studied by these very same two techniques. So how do we get to 100% error in Greenland measurements?
Title: Re: What's new in Antarctica ?
Post by: Lennart van der Linde on October 14, 2015, 11:17:37 PM
New study by Golledge et al on Antarctic ice loss projections for the coming centuries/millennia:
http://nature.com/articles/doi:10.1038/nature15706 (http://nature.com/articles/doi:10.1038/nature15706)
Title: Re: What's new in Antarctica ?
Post by: Wipneus on October 16, 2015, 07:22:11 AM
NSIDC announced Antarctic sea ice maximum on October the 6th.

http://nsidc.org/arcticseaicenews/2015/10/antarctic-sea-ice-at-its-2015-maximum/ (http://nsidc.org/arcticseaicenews/2015/10/antarctic-sea-ice-at-its-2015-maximum/)

2015 was not record high:

Quote
It is likely that this slowing of late-winter ice growth is related in part to the build-up of the El Niño conditions.
(...)
Patterns of sea ice concentration around Antarctica (the deviation from average ice concentration) for El Niño years show a similar pattern, with more ice near the Peninsula.


(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fnsidc.org%2Farcticseaicenews%2Ffiles%2F2015%2F10%2FFigure41.png&hash=c314b4fb433e5a355cc9c016752aed2d)
Title: Re: What's new in Antarctica ?
Post by: crandles on October 16, 2015, 03:30:04 PM
NSIDC
Quote
Only one year, 2002, has had a later maximum (October 12).

However area maximum reached on day 248 is equal 8th earliest area maximum.

Early area maximum and late extent maximum would, I guess, be another sign of the 'slowing of late-winter ice growth'  that is likely due to El Nino.

(The years with earlier area maximums: 2010 2004 2002 1994 1992 have at least some El Nino nearby even if 1989 and 1985 do not.)
Title: Re: What's new in Antarctica ?
Post by: Timothy Astin on October 16, 2015, 03:30:58 PM
Hansen and Sato's manuscript paper

http://www.columbia.edu/~jeh1/mailings/2015/20151012_IceMeltPredictions.pdf (http://www.columbia.edu/~jeh1/mailings/2015/20151012_IceMeltPredictions.pdf)

(earlier version dated 21st September was the subject of a brief forum thread https://forum.arctic-sea-ice.net/index.php/topic,1406.0.html (https://forum.arctic-sea-ice.net/index.php/topic,1406.0.html))

They also comment on the EL Nino impact on 2015 winter extent of Antarctic sea ice.  The map in Wpneus' post shows the positive anomalies in ice being particularly in the western hemisphere, especially west of the Antactic peninsula, which is where Hansen and Sato predict the maximum outflow of land-ice meltwater, a pattern they predict to intensify.
Title: Re: What's new in Antarctica ?
Post by: Timothy Astin on October 16, 2015, 03:59:01 PM
New study by Golledge et al on Antarctic ice loss projections for the coming centuries/millennia:
http://nature.com/articles/doi:10.1038/nature15706 (http://nature.com/articles/doi:10.1038/nature15706)

Anyone got access to the full article care to comment on this paper?  From the abstract and publically available figures, it appears "conservative" in its predictions compared to other recent papers, presumably because of the viscous ice model used.  But I'd need to read the text to make a judgement.

Even if the paper's predictions are at the lower end of best current knowledge (as I think they probably are), its predictions for sea level change have all sorts of implications.

Just one example local to me. The regional council are keen to build some 7000 new houses on the Trent coastal floodplain, and planning officers advised by the UK Environment Agency believe that it will remain above water in 85 years time.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on October 16, 2015, 08:39:26 PM
The linked reference finds that wind induced snow mass loss from East Antarctica is dominated by sublimation with the mass transported downwind as water vapor.  This new finding indicates that the AIS contribution to SLR will be greater than previously recognized:

Indrani Das, Ted A. Scambos, Lora S. Koenig, Michiel R. van den Broeke, Jan T. M. Lenaerts (2015), "Extreme wind-ice interaction over Recovery Ice Stream, East Antarctica", Geophysical Research Letters, by DOI: 10.1002/2015GL065544

http://onlinelibrary.wiley.com/doi/10.1002/2015GL065544/abstract (http://onlinelibrary.wiley.com/doi/10.1002/2015GL065544/abstract)

Abstract: "Surface snow accumulation over East Antarctica is an important climate indicator but a difficult parameter to constrain. Surface mass ablation dominates over persistent wind-scour zones as near-surface katabatic winds accelerate over locally steeper ice surface topography, and sublimate and redistribute snow. Here we quantify ablation rates and downwind redeposition of snow over wind-scour zones in the upper Recovery Ice Stream catchment. Airborne radio echo-soundings show a gradual ablation of ~16–18 m of firn, corresponding to ~200 years of accumulation, over these zones and ablation rates of ~54 kg m−2 a−1 (54 mm water equivalent a−1). We conclude that mass loss is dominated by sublimation and mass is transported downwind as water vapor, because snow redeposition downslope of the wind-scour zones constitutes only a small fraction (<10%) of the cumulative mass loss."
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on October 18, 2015, 06:48:23 PM
The following article provides an overview while siding a little on the side of least drama (as most of the published reports that it cites are):

http://www.smh.com.au/environment/antarctica-trouble-at-the-edge-of-the-world-20151013-gk7w4m.html (http://www.smh.com.au/environment/antarctica-trouble-at-the-edge-of-the-world-20151013-gk7w4m.html)
Title: Re: What's new in Antarctica ?
Post by: Laurent on October 19, 2015, 05:12:02 PM
Warming Oceans May Threaten Krill, a Cornerstone of the Antarctic Ecosystem
http://www.nytimes.com/2015/10/20/science/australia-antarctica-krill-climate-change-ocean.html?partner=rss&emc=rss (http://www.nytimes.com/2015/10/20/science/australia-antarctica-krill-climate-change-ocean.html?partner=rss&emc=rss)
Quote
“We thought the krill might be more robust,” said Dr. Kawaguchi, a biologist who works for the Australian government’s Antarctic Division. “We were not expecting such a clear result.”
Title: Re: What's new in Antarctica ?
Post by: Laurent on November 26, 2015, 11:49:06 AM
Big data reveals glorious animation of Antarctic bottom water
http://nci.org.au/2015/11/24/big-data-reveals-glorious-animation-of-antarctic-bottom-water/ (http://nci.org.au/2015/11/24/big-data-reveals-glorious-animation-of-antarctic-bottom-water/)

https://www.youtube.com/watch?feature=player_embedded&v=8VMSF28J9H4 (https://www.youtube.com/watch?feature=player_embedded&v=8VMSF28J9H4)
Title: Re: What's new in Antarctica ?
Post by: A-Team on November 26, 2015, 04:57:53 PM
That's a fabulous animation from the technical standpoint, worth watching over and over. To phong-render this many frames at this HD resolution might take months on a personal computer.

It also very good at making its talking points which, being inherently 3D, are very difficult to convey with a cartoon or explain in verbiage.

The main quibble would be, how could the underlying experimental data possibly be reliable over a vast area that is rarely and sparsely sampled and not visible to satellite? The response: it is entirely the output of a model, presumably constrained to the little concrete data that exists. This doesn't matter too much if what it is conveying is a representative simulation of actual conditions.

[Update: just noticed a quote "so much data was used, that it took seven hours to process just one second of the animation." http://nci.org.au/2015/11/24/big-data-reveals-glorious-animation-of-antarctic-bottom-water/ (http://nci.org.au/2015/11/24/big-data-reveals-glorious-animation-of-antarctic-bottom-water/)]
Title: Re: What's new in Antarctica ?
Post by: oren on November 27, 2015, 02:16:17 PM
Beautiful animation
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 03, 2015, 12:12:08 AM
The linked article discusses the first commercial air flight to Antarctica as well as possible future commercial flights:

http://www.popularmechanics.com/flight/news/a18380/first-commercial/ (http://www.popularmechanics.com/flight/news/a18380/first-commercial/)

Extract: "On November 26, a commercial Boeing 747 passenger jet successfully landed on a blue-ice field in Antarctica for the first time. The landing was organized by Antarctic Logistics & Expeditions (ALE), and the airliner was piloted by Loftleidir Icelandic as "part of a larger investigation into the use of such aircraft for ALE's Antarctic operations."
The Boeing 747 was landed on Union Glacier, near ALE's primary camp. ALE transports between 400 and 500 people to Antarctica each year, primarily scientists traveling to the frigid continent to conduct research projects. Passengers have traditionally traveled in combination cargo/passenger planes that are well equipped to handle ice landings, such as the Lockheed L 100 Hercules and Ilyushin Il-76. "The Boeing 757-200 ER, fitted with 62 business class seats, will enhance passenger comfort yet maintain the safety of ALE's activities and aircraft resources," says ALE.
Successfully landing passenger airliners on Antarctica also opens the door for tourism and recreational trips. Traditionally, travelers to Antarctica who are not part of an official scientific expedition have arrived in boats from Chile or South Africa."
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 03, 2015, 12:41:41 AM
 The linked article discusses how the Halley VI British Antarctic Station is being relocated this Austral Summer to avoid being part of a major calving event for the Brunt Ice Shelf (see that attached image):

https://www.newscientist.com/article/dn28600-massive-crevasse-in-the-ice-forces-early-move-for-antarctic-base/ (https://www.newscientist.com/article/dn28600-massive-crevasse-in-the-ice-forces-early-move-for-antarctic-base/)

Extract: "Life on a floating ice shelf is precarious enough, but when a massive crack is heading your way, you know you’re in trouble. This nightmare scenario is what’s forcing the UK’s newest research station in Antarctica to relocate.

Halley VI opened in 2013 to much fanfare due to its space-age design. It’s built as eight modules on skisso that it can be towed to a new location if the ice conditions change.



The crack is extending in the direction of Halley VI at a rate of 1.7 km a year, and is 8 km away from the base. “We don’t know what will happen,” says Gudmundsson. “It might stop growing, but we can’t exclude the possibility of a big calving event.”
The main concern is that Chasm 1 will grow so much that it makes it impossible to relocate the base in the future. That’s why a move is now underway."
Title: Re: What's new in Antarctica ?
Post by: Laurent on December 04, 2015, 08:08:58 PM
Rising atmospheric carbon dioxide actually cools part of Antarctica
http://news.sciencemag.org/environment/2015/12/rising-atmospheric-carbon-dioxide-actually-cools-part-antarctica (http://news.sciencemag.org/environment/2015/12/rising-atmospheric-carbon-dioxide-actually-cools-part-antarctica)

Quote
In a world where most regions are warming because of increasing concentrations of atmospheric carbon dioxide (CO2), central Antarctica has been cooling slightly in recent years. Greenhouse gases such as CO2 typically trap heat radiated back toward space from the planet’s surface, but large swaths of the East Antarctic Ice Sheet (the broad pink mass on the right side of the image) are, on average, actually colder than the upper layers of the atmosphere for much of the year—the only place on Earth where that’s true. When the team looked at the overall balance between the radiation upward from the surface of the ice sheet and the radiation both upward and downward from the upper levels of the atmosphere across all infrared wavelengths over the course of a year, they found that in central Antarctica the surface and lower atmosphere, against expectation, actually lose more energy to space if the air contains greenhouse gases, the researchers report online and in a forthcoming Geophysical Research Letters. And adding more CO2 to the atmosphere in the short-term triggered even more energy loss from the surface and lower atmosphere there, the team’s climate simulations suggest. The topsy-turvy temperature trend stems, in part, from the region’s high elevation; much of the surface of the ice sheet smothering East Antarctica lies above an elevation of 3000 meters, so it is much colder than it would be at lower altitudes. Moreover, that region often experiences what meteorologists call a temperature inversion, where temperatures in the lowest levels of the atmosphere are cooler than those higher up. For the lower-altitude fringes of the icy continent, and for the rest of the world (even Siberia and Greenland), the greenhouse effect still works as expected.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 04, 2015, 08:16:28 PM
Rising atmospheric carbon dioxide actually cools part of Antarctica

What they don't note is that this effect will help sustain strong circumpolar wind speeds as the ozone hole heals itself, thus maintaining the advection of unusually high volumes of warm CDW to the grounding lines of key Antarctic marine glaciers (like PIG).
Title: Re: What's new in Antarctica ?
Post by: oren on December 25, 2015, 03:04:40 PM
Rising atmospheric carbon dioxide actually cools part of Antarctica
http://news.sciencemag.org/environment/2015/12/rising-atmospheric-carbon-dioxide-actually-cools-part-antarctica (http://news.sciencemag.org/environment/2015/12/rising-atmospheric-carbon-dioxide-actually-cools-part-antarctica)

Quote
In a world where most regions are warming because of increasing concentrations of atmospheric carbon dioxide (CO2), central Antarctica has been cooling slightly in recent years. Greenhouse gases such as CO2 typically trap heat radiated back toward space from the planet’s surface, but large swaths of the East Antarctic Ice Sheet (the broad pink mass on the right side of the image) are, on average, actually colder than the upper layers of the atmosphere for much of the year—the only place on Earth where that’s true. When the team looked at the overall balance between the radiation upward from the surface of the ice sheet and the radiation both upward and downward from the upper levels of the atmosphere across all infrared wavelengths over the course of a year, they found that in central Antarctica the surface and lower atmosphere, against expectation, actually lose more energy to space if the air contains greenhouse gases, the researchers report online and in a forthcoming Geophysical Research Letters. And adding more CO2 to the atmosphere in the short-term triggered even more energy loss from the surface and lower atmosphere there, the team’s climate simulations suggest. The topsy-turvy temperature trend stems, in part, from the region’s high elevation; much of the surface of the ice sheet smothering East Antarctica lies above an elevation of 3000 meters, so it is much colder than it would be at lower altitudes. Moreover, that region often experiences what meteorologists call a temperature inversion, where temperatures in the lowest levels of the atmosphere are cooler than those higher up. For the lower-altitude fringes of the icy continent, and for the rest of the world (even Siberia and Greenland), the greenhouse effect still works as expected.

Interesting, though an anecdote in the grand scheme of things.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 29, 2015, 04:28:16 PM
The linked New York Times article discusses how new technology is making Antarctica more accessible to more countries; which are jockeying for strategic & commercial opportunities:

http://www.nytimes.com/interactive/2015/12/29/world/countries-rush-for-upper-hand-antarctica.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=photo-spot-region&region=top-news&WT.nav=top-news&_r=0 (http://www.nytimes.com/interactive/2015/12/29/world/countries-rush-for-upper-hand-antarctica.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=photo-spot-region&region=top-news&WT.nav=top-news&_r=0)

Extract: "But an array of countries are rushing to assert greater influence here, with an eye not just toward the day those protective treaties expire, but also for the strategic and commercial opportunities that exist right now.
“The newer players are stepping into what they view as a treasure house of resources,” said Anne-Marie Brady, a scholar at New Zealand’s University of Canterbury who specializes in Antarctic politics.
Some of the ventures focus on the Antarctic resources that are already up for grabs, like abundant sea life. China and South Korea, both of which operate state-of-the-art bases here, are ramping up their fishing of krill, the shrimplike crustaceans found in abundance in the Southern Ocean, while Russia recently thwarted efforts to create one of the world’s largest ocean sanctuaries here.
Some scientists are examining the potential for harvesting icebergs from Antarctica, which is estimated to have the biggest reserves of fresh water on the planet. Nations are also pressing ahead with space research and satellite projects to expand their global navigation abilities.
Building on a Soviet-era foothold, Russia is expanding its monitoring stations for Glonass, its version of the Global Positioning System. At least three Russian stations are already operating in Antarctica, part of its effort to challenge the dominance of the American GPS, and new stations are planned for sites like the Russian base, in the shadow of the Orthodox Church of the Holy Trinity.



“The old days of the Antarctic being dominated by the interests and wishes of white men from European, Australasian and North American states is over,” said Klaus Dodds, a politics scholar at the University of London who specializes in Antarctica. “The reality is that Antarctica is geopolitically contested.”"
Title: Re: What's new in Antarctica ?
Post by: Stephen on December 30, 2015, 12:18:43 AM
Quote
...Some scientists are examining the potential for harvesting icebergs from Antarctica, w...

It's been done. (http://hoaxes.org/af_database/permalink/the_sydney_iceberg/)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.smh.com.au%2FffxImage%2Furlpicture_id_1048653852095_2003%2F03%2F28%2Fnws_320dicksmith%2C0.jpg&hash=ea361740b76702ed526620e2d9c8f061)


Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 04, 2016, 11:25:49 PM
The linked (open access) reference leads to an assessment of using GRACE data to estimate ice mass loss from Antarctica in the 2003 to 2009 timeframe:

Zammit-Mangion, Andrew; Bamber, Jonathan L.; Schoen, Nana W.; Rougier, Jonathan C. (2015), "A data-driven approach for assessing ice-sheet mass balance in space and time", Annals of Glaciology, Volume 56, Number 70, DOI: http://dx.doi.org/10.3189/2015AoG70A021 (http://dx.doi.org/10.3189/2015AoG70A021)


http://www.ingentaconnect.com/content/igsoc/agl/2015/00000056/00000070/art00020?token=005c1c0cf32784d772646e586546243125425747794c7d786c255c5e4e2663433b393f6a333f25667ef295853a2a (http://www.ingentaconnect.com/content/igsoc/agl/2015/00000056/00000070/art00020?token=005c1c0cf32784d772646e586546243125425747794c7d786c255c5e4e2663433b393f6a333f25667ef295853a2a)

Abstract: "Combinations of various numerical models and datasets with diverse observation characteristics have been used to assess the mass evolution of ice sheets. As a consequence, a wide range of estimates have been produced using markedly different methodologies, data, approximation methods and model assumptions. Current attempts to reconcile these estimates using simple combination methods are unsatisfactory, as common sources of errors across different methodologies may not be accurately quantified (e.g. systematic biases in models). Here we provide a general approach which deals with this issue by considering all data sources simultaneously, and, crucially, by reducing the dependence on numerical models. The methodology is based on exploiting the different space–time characteristics of the relevant ice-sheet processes, and using statistical smoothing methods to establish the causes of the observed change. In omitting direct dependence on numerical models, the methodology provides a novel means for assessing glacio-isostatic adjustment and climate models alike, using remote-sensing datasets. This is particularly advantageous in Antarctica, where in situ measurements are difficult to obtain. We illustrate the methodology by using it to infer Antarctica's mass trend from 2003 to 2009 and produce surface mass-balance anomaly estimates to validate the RACMO2.1 regional climate model."
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 06, 2016, 07:55:14 PM
Short post about new seismic monitoring stations getting installed:
http://earthsky.org/earth/new-glimpse-of-geology-under-antarcticas-ice (http://earthsky.org/earth/new-glimpse-of-geology-under-antarcticas-ice)
"Using technology built to withstand the harsh winters, scientists have managed to map the volcanos, rifts, and basins hidden under West Antarctica’s ice sheet."
Title: Re: What's new in Antarctica ?
Post by: Espen on January 06, 2016, 08:59:59 PM
We are heading for a record low or something similar this year, that is my unqualified estimate:
Title: Re: What's new in Antarctica ?
Post by: Buddy on January 06, 2016, 09:39:23 PM
Quote
We are heading for a record low or something similar this year, that is my unqualified estimate

And there is a nice fairly "significant warm anomaly" in the southern Pacific (between New Zealand and southern Chile) that has been gaining strength (warmth) over the past few weeks....

Not good....

Title: Re: What's new in Antarctica ?
Post by: Buddy on January 06, 2016, 09:40:43 PM
Warm anomaly in southern Pacific....

http://climatechangegraphs.blogspot.com/2013/02/sea-surface-temperature-anomaly.html (http://climatechangegraphs.blogspot.com/2013/02/sea-surface-temperature-anomaly.html)
Title: Re: What's new in Antarctica ?
Post by: Espen on January 06, 2016, 10:46:49 PM
It is definitely heading south:
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 06, 2016, 10:53:37 PM
It is definitely heading south:

Most likely this is due to the near El Nino in 2014 and the current Super 2015-16 El Nino that is creating anomalously high surface temperatures in Western Antarctica (see attached image of the 5-day average anom forecast)
Title: Re: What's new in Antarctica ?
Post by: sidd on January 07, 2016, 07:07:12 AM
Where would you say Mercer's canary, the 0C midsummer isotherm will wind up this year ? i suppose the 0C isotherm for December-Jan averaged is a good enuf approximation, thats whats i look at on merra and such, i wonder what it will look like this year
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 07, 2016, 05:00:04 PM
Where would you say Mercer's canary, the 0C midsummer isotherm will wind up this year ? i suppose the 0C isotherm for December-Jan averaged is a good enuf approximation, thats whats i look at on merra and such, i wonder what it will look like this year

sidd,

The first attached image is the Nullschool Earth Surface Wind and Temperature forecast for January 11, 2016.  The green color is above freezing, so the 0C isotherm on that day will be right around the edges of the Pine Island Bay, will could cause hydrofracture for either the PIG or the Thwaites Glacier later this austral summer.

Best,
ASLR

Edit the second attached image shows the Nullschool Earth 1000-hPa Wind and Temperature forecast for Jan 11 2016, showing that the coastline (at 1000-hPa) from the Ross Sea to Pine Island Bay is projected to be above freezing on that date.
Title: Re: What's new in Antarctica ?
Post by: Laurent on January 13, 2016, 08:40:53 PM
'Gigantic chasm under Antarctic ice'
http://www.bbc.com/news/science-environment-35303779 (http://www.bbc.com/news/science-environment-35303779)
Quote
A vast, previously unrecognised canyon system could be hidden under the Antarctic ice sheet.

Hints of its presence are seen in the shape of the white continent's surface, in a largely unexplored region called Princess Elizabeth Land.

If confirmed by a proper geophysical survey - now under way - the winding canyon network would be over 1,000km long and in places as much as 1km deep.

These dimensions would make it bigger than the famous Grand Canyon in the US.

"We know from other areas of Antarctica that the shape of the ice surface is obviously dependent on the shape of the landscape underneath - because the ice is flowing over that landscape," explained Dr Stewart Jamieson, from Durham University, UK.

"When we look in Princess Elizabeth Land with satellite data, there seem to be some linear features in the surface ice that to us look very reminiscent of a canyon.

"We have traced these faint lineations from the centre of Princess Elizabeth Land all the way to the coast, off to the north. It's a pretty substantial system," he told BBC News.

There are suggestions also that the canyon network is connected to a previously undiscovered subglacial lake.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 14, 2016, 11:00:37 PM
'Gigantic chasm under Antarctic ice'
http://www.bbc.com/news/science-environment-35303779 (http://www.bbc.com/news/science-environment-35303779)
Quote
A vast, previously unrecognised canyon system could be hidden under the Antarctic ice sheet.

Hints of its presence are seen in the shape of the white continent's surface, in a largely unexplored region called Princess Elizabeth Land.

If confirmed by a proper geophysical survey - now under way - the winding canyon network would be over 1,000km long and in places as much as 1km deep.

These dimensions would make it bigger than the famous Grand Canyon in the US.

"We know from other areas of Antarctica that the shape of the ice surface is obviously dependent on the shape of the landscape underneath - because the ice is flowing over that landscape," explained Dr Stewart Jamieson, from Durham University, UK.

"When we look in Princess Elizabeth Land with satellite data, there seem to be some linear features in the surface ice that to us look very reminiscent of a canyon.

"We have traced these faint lineations from the centre of Princess Elizabeth Land all the way to the coast, off to the north. It's a pretty substantial system," he told BBC News.

There are suggestions also that the canyon network is connected to a previously undiscovered subglacial lake.

While I do not expect that this new finding will have any implication in my lifetime, I thought that it would not hurt to provide a more complete reference citation:

Stewart S.R. Jamieson, Neil Ross, Jamin S. Greenbaum, Duncan A. Young, Alan R.A. Aitken, Jason L. Roberts, Donald D. Blankenship, Sun Bo and Martin J. Siegert (2015), "An extensive subglacial lake and canyon system in Princess Elizabeth Land, East Antarctica", Geology, doi: 10.1130/G37220.1


http://geology.gsapubs.org/content/early/2015/12/22/G37220.1.abstract (http://geology.gsapubs.org/content/early/2015/12/22/G37220.1.abstract)


Abstract: "The subglacial landscape of Princess Elizabeth Land (PEL) in East Antarctica is poorly known due to a paucity of ice thickness measurements. This is problematic given its importance for understanding ice sheet dynamics and landscape and climate evolution. To address this issue, we describe the topography beneath the ice sheet by assuming that ice surface expressions in satellite imagery relate to large-scale subglacial features. We find evidence that a large, previously undiscovered subglacial drainage network is hidden beneath the ice sheet in PEL. We interpret a discrete feature that is 140 × 20 km in plan form, and multiple narrow sinuous features that extend over a distance of ∼1100 km. We hypothesize that these are tectonically controlled and relate to a large subglacial basin containing a deep-water lake in the interior of PEL linked to a series of long, deep canyons. The presence of 1-km-deep canyons is confirmed at a few localities by radio-echo sounding data, and drainage analysis suggests that these canyons will direct subglacial meltwater to the coast between the Vestfold Hills and the West Ice Shelf."
Title: Re: What's new in Antarctica ?
Post by: Sigmetnow on January 19, 2016, 12:04:30 AM
Astronaut aboard the International Space Station photographs massive iceberg in southern ocean.

Quote
Scott Kelly: Just spotted this massive iceberg in the southern Indian Ocean. #YearInSpace

https://twitter.com/stationcdrkelly/status/689182696845750272

Quote
Olivia D'Souza:  @StationCDRKelly I believe it is Iceberg C-16 near Ross Island @PC0101 @DaveAtCOGS @gavinmcmorrow @CaliaDomenico

https://twitter.com/olivia_dsouza/status/689185273612091394
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 27, 2016, 04:18:27 PM
The linked article indicates that Kiwi geologists are studying fossils near Mt Discovery, Antarctica, that could shed light on the risk of portions of the EAIS collapsing as the current climate approaches Pliocene conditions:

http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11576382 (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11576382)

Extract: "Call it extreme geology: a team of Kiwi scientists is venturing to a remote part of Antarctica to dig up ancient evidence of a warmer world.
The treasure trove of fossilised marine life buried in the rock near Mt Discovery - about 50km from Scott Base - could help us better understand what might happen to our planet under future climate change.
It's a place exposed to the continent's unforgiving weather - including 150km/h wind storms that recently shredded tents at a US camp.
The expedition, led by Dr Richard Levy of GNS Science and Professor Tim Naish of Victoria University's Antarctic Research Centre, aims to follow up descriptions of a similar site found nearby about 50 years ago.
The discoverers found shells of organisms that could not live in the sea ice that covers the environment today.
"The samples are telling us it was a warmer world, but we want to know when that was and how old the deposit is; we think it's probably from about three million years ago," said Professor Naish. "This period is a pretty important window for understanding what might happen with global warming."
Called the Pliocene, it was the most recent time when there were 400 parts per million of carbon dioxide in the Earth's atmosphere.
That same level has been reached today through the human carbon emissions projected to heat the climate by several degrees by 2200.

While sensitive areas of the West Antarctic Ice Sheet such as Pine Island were important because they were already experiencing rapid mass loss and melting, Mt Discovery provided evidence of what the much larger East Antarctic Ice Sheet may have done during the warmer ancient climate.
"The thing is, when this place starts to melt, it's the last to go - so you know you're in real trouble.""
Title: Re: What's new in Antarctica ?
Post by: wili on January 27, 2016, 05:29:08 PM
Apologies if this has already been posted somewhere, and hat tip to Hank Roberts at RealClimate for the link:

http://onlinelibrary.wiley.com/doi/10.1002/2015GL066612/abstract (http://onlinelibrary.wiley.com/doi/10.1002/2015GL066612/abstract)

Oliver J. Marsh, Helen A. Fricker, Matthew R. Siegfried, Knut Christianson, Keith W. Nicholls, Hugh F. J. Corr, Ginny Catania
First published: 14 January 2016
DOI: 10.1002/2015GL066612

High basal melting forming a channel at the grounding line of Ross Ice Shelf, Antarctica

Quote

Antarctica’s ice shelves are thinning at an increasing rate, affecting their buttressing ability. Channels in the ice shelf base unevenly distribute melting, and their evolution provides insight into changing subglacial and oceanic conditions. Here we used phase-sensitive radar measurements to estimate basal melt rates in a channel beneath the currently stable Ross Ice Shelf.

Melt rates of 22.2 ± 0.2 m a−1 (>2500% the overall background rate) were observed 1.7 km seaward of Mercer/Whillans Ice Stream grounding line, close to where subglacial water discharge is expected. Laser altimetry shows a corresponding, steadily deepening surface channel.

Two relict channels to the north suggest recent subglacial drainage reorganization beneath Whillans Ice Stream approximately coincident with the shutdown of Kamb Ice Stream. This rapid channel formation implies that shifts in subglacial hydrology may impact ice shelf stability.
Title: Re: What's new in Antarctica ?
Post by: cats on February 02, 2016, 08:28:49 PM
An interesting project to get more info on Antarctic ice shelves http://polarfever.com/2016/02/02/physical-oceanographers-on-ice/ (http://polarfever.com/2016/02/02/physical-oceanographers-on-ice/)

Summary -
 The phase sensitive radars were developed and built at the British Antarctic Survey (BAS) and very precisely measure changes in ice thickness. This means that we get a direct measurement of the ice shelf melt rate. Satellites can also be used to measure this, but will only give average values over several years, while we will get a value every 2 hours from the phase sensitive radars. In combination with the moorings that we have deployed at the ice shelf front, this will allow us to directly link changes in ocean temperature to changes in the ice shelf melt rate. The aim of the seismic surveys is to find out how much seawater there is between the floating ice shelf and the bedrock.
Title: Re: What's new in Antarctica ?
Post by: Sigmetnow on February 05, 2016, 03:38:40 AM
Scar Inlet ice shelf said to be poised to disintegrate.

Glaciologists anticipate massive ice shelf collapse
Quote
Since late 2011, the larger bay where the Larsen B once resided has been covered with a solid sheet of frozen ocean ice, called ‘fast ice’ because it is ‘fastened’ or frozen to the coastline,” Scambos said. “We suspect this ice is supporting the weakened Scar Inlet ice shelf and that the shelf is poised to break up if the thin fast ice breaks away. One good windstorm could set some of this process in motion.”
http://news.uaf.edu/61609-2/ (http://news.uaf.edu/61609-2/)
Title: Re: What's new in Antarctica ?
Post by: A-Team on February 09, 2016, 12:28:50 PM
Sounds like this could be monitored just as easily from home. The article does not provide the Landsat accession number that would make this easier for us. Sentinel 1A radar could make a nice adjunct. I am skeptical that they will be measuring anything out there on the ice under this breakup scenario -- it seems to be more for experiencing the experience. Oh well, it could make for a neat video.

Quote
Scambos said the Scar Inlet ice shelf has been showing signs of increased melting and large-scale fracturing over the past 14 years. The only support holding back more fracturing could be the 6 to 10 feet of frozen ocean in front of it — a thin, fragile crust compared to the ice shelf plate.

“Since late 2011, the larger bay where the Larsen B once resided has been covered with a solid sheet of frozen ocean ice, called ‘fast ice’ because it is ‘fastened’ or frozen to the coastline,” Scambos said. “We suspect this ice is supporting the weakened Scar Inlet ice shelf and that the shelf is poised to break up if the thin fast ice breaks away. One good windstorm could set some of this process in motion.”

“This will be the first time anybody records ground-based data from an ice shelf that is ready to break up,” Truffer said. “The prize, of course, would be to witness the actual break-up, but, even if we miss that, we will have a detailed record of ongoing weakening of the shelf. An unnamed mountaineer from the British Antarctic Survey will help them navigate.”
Title: Re: What's new in Antarctica ?
Post by: Laurent on February 13, 2016, 11:41:53 AM
150,000 penguins die after giant iceberg renders colony landlocked
http://www.theguardian.com/world/2016/feb/13/150000-penguins-killed-after-giant-iceberg-renders-colony-landlocked (http://www.theguardian.com/world/2016/feb/13/150000-penguins-killed-after-giant-iceberg-renders-colony-landlocked)
Quote
Penguins of Cape Denison in Antarctica effectively trapped by iceberg the size of Rome and face 120km round trip to feed
There are fears the colony of Adelie penguins will be wiped out in 20 years’ time unless the iceberg moves.
There are fears the colony of Adelie penguins will be wiped out in 20 years’ time unless the iceberg moves. Photograph: Alamy

Guardian staff

Saturday 13 February 2016 06.56 GMT
Last modified on Saturday 13 February 2016 10.15 GMT

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An estimated 150,000 Adelie penguins living in Antarctica have died after an iceberg the size of Rome became grounded near their colony, forcing them to trek 60km to the sea for food.

The penguins of Cape Denison in Commonwealth Bay used to live close to a large body of open water. However, in 2010 a colossal iceberg measuring 2900sq km became trapped in the bay, rendering the colony effectively landlocked.
Penguins suffering from climate change, scientists say
Read more

Penguins seeking food must now waddle 60km to the coast to fish. Over the years, the arduous journey has had a devastating effect on the size of the colony.

Since 2011 the colony of 160,000 penguins has shrunk to just 10,000, according to research carried out by the Climate Change Research Centre at Australia’s University of New South Wales. Scientists predict the colony will be gone in 20 years unless the sea ice breaks up or the giant iceberg, dubbed B09B, is dislodged.

Penguins have been recorded in the area for more than 100 years. But the outlook for the penguins remaining at Cape Denison is dire.

“The arrival of iceberg B09B in Commonwealth Bay, East Antarctica, and subsequent fast ice expansion has dramatically increased the distance Adélie penguins breeding at Cape Denison must travel in search of food,” said the researchers in an article in Antarctic Science.

“The Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out”

“This has provided a natural experiment to investigate the impact of iceberg stranding events and sea ice expansion along the East Antarctic coast.”

In contrast, a colony located just 8km from the coast of Commonwealth Bay is thriving, the researchers said.

The iceberg had apparently been floating close to the coast for 20 years before crashing into a glacier and becoming stuck.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on February 17, 2016, 11:31:24 AM
While the linked Dec 2015 article is not exactly news, it does present a long discussion of some of the key issues associated with the risk of rapid ice sheet mass loss in the coming decades/centuries:


http://www.irishexaminer.com/lifestyle/features/the-long-read-are-the-secrets-we-need-to-battle-climate-change-hidden-in-the-glaciers-369801.html (http://www.irishexaminer.com/lifestyle/features/the-long-read-are-the-secrets-we-need-to-battle-climate-change-hidden-in-the-glaciers-369801.html)

Extract: "When I asked Richard Alley, almost certainly the most respected glaciologist in the United States, whether he would be surprised to see Thwaites collapse in his lifetime, he drew a breath. Alley is 58. “Up until very recently, I would have said, ‘Yes, I’d be surprised,’” he told me. “Right now, I’m not sure. I’m still cautiously optimistic that in my life, Thwaites has got enough stability on the ridge where it now sits that I will die before it does. But I’m not confident about that for my kids. And if someday I have grandkids, I’m not at all confident for them.”

Rignot answers the same question more bluntly. “That’s what we’re seeing right now — they are in a state of collapse,” he says. “We’ve never seen it before, so it’s hard to identify it and say, ‘We know exactly what it looks like, and this is what it looks like.’ We’re still in the early stage.”

Rignot predicts that in 30 or 40 years, people will be accustomed to watching Thwaites and Pine Island disintegrate constantly, iceberg by iceberg, into the ocean."

Edit: Personally, I think that Rignot should be the most respected glaciologist in the US.
Title: Re: What's new in Antarctica ?
Post by: jimbenison on February 18, 2016, 08:12:11 PM
150,000 penguins die after giant iceberg renders colony landlocked
http://www.theguardian.com/world/2016/feb/13/150000-penguins-killed-after-giant-iceberg-renders-colony-landlocked (http://www.theguardian.com/world/2016/feb/13/150000-penguins-killed-after-giant-iceberg-renders-colony-landlocked)
Quote
Penguins of Cape Denison in Antarctica effectively trapped by iceberg the size of Rome and face 120km round trip to feed
There are fears the colony of Adelie penguins will be wiped out in 20 years’ time unless the iceberg moves.
There are fears the colony of Adelie penguins will be wiped out in 20 years’ time unless the iceberg moves. Photograph: Alamy

Guardian staff

Saturday 13 February 2016 06.56 GMT
Last modified on Saturday 13 February 2016 10.15 GMT

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An estimated 150,000 Adelie penguins living in Antarctica have died after an iceberg the size of Rome became grounded near their colony, forcing them to trek 60km to the sea for food.

The penguins of Cape Denison in Commonwealth Bay used to live close to a large body of open water. However, in 2010 a colossal iceberg measuring 2900sq km became trapped in the bay, rendering the colony effectively landlocked.
Penguins suffering from climate change, scientists say
Read more

Penguins seeking food must now waddle 60km to the coast to fish. Over the years, the arduous journey has had a devastating effect on the size of the colony.

Since 2011 the colony of 160,000 penguins has shrunk to just 10,000, according to research carried out by the Climate Change Research Centre at Australia’s University of New South Wales. Scientists predict the colony will be gone in 20 years unless the sea ice breaks up or the giant iceberg, dubbed B09B, is dislodged.

Penguins have been recorded in the area for more than 100 years. But the outlook for the penguins remaining at Cape Denison is dire.

“The arrival of iceberg B09B in Commonwealth Bay, East Antarctica, and subsequent fast ice expansion has dramatically increased the distance Adélie penguins breeding at Cape Denison must travel in search of food,” said the researchers in an article in Antarctic Science.

“The Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out”

“This has provided a natural experiment to investigate the impact of iceberg stranding events and sea ice expansion along the East Antarctic coast.”

In contrast, a colony located just 8km from the coast of Commonwealth Bay is thriving, the researchers said.

The iceberg had apparently been floating close to the coast for 20 years before crashing into a glacier and becoming stuck.

Some are suggesting that the penguins haven't died; they just moved.

http://news.discovery.com/animals/dead-antarctica-penguins-are-probably-fine-160216.htm (http://news.discovery.com/animals/dead-antarctica-penguins-are-probably-fine-160216.htm)

Also, it appears that the fast ice cleared out of Commonwealth Bay on about the 15th. The berg is still there though.
Title: Re: What's new in Antarctica ?
Post by: sidd on February 19, 2016, 05:58:06 AM
Lets be clear about this. They didn't just move. We evicted them. And they have no lobbyists in Beiging, Brussels or Washington, or at least not any who have as much money as fossil interests.
Title: Re: What's new in Antarctica ?
Post by: bligh8 on February 20, 2016, 04:35:37 PM
Don’t look now Mr. Sidd,  but your empathetic values are showing……again.
Title: Re: What's new in Antarctica ?
Post by: sidd on February 21, 2016, 07:10:12 AM
"empathetic values are showing……again."

o dear, i must tuck them back in.

But it does irk me that we humans bewail inconvenience from ice sheet collapse, while almost entirely ignoring the harm it does and will do to a myriad other live things. We live in vast ecology, and we are burning so, so much of structure beneath our feet, and the obscenity is that _we do not even know_ who or how many we kill.

Truly, we believe absurdities, so we commit atrocities.

sidd
Title: Re: What's new in Antarctica ?
Post by: wili on February 21, 2016, 08:48:40 AM
" we believe absurdities, so we commit atrocities" Nice Voltaire paraphrase!
Title: Re: What's new in Antarctica ?
Post by: bligh8 on February 21, 2016, 03:20:56 PM
Wili

Voltaire seemed a bit much for me, but Nietzsche, Byron, Blake and  Shelly were more of my thinking.  In keeping with the title thread…I recall Shelly's "The Cloud" where every word was intrinsically interwoven with the last and next… it brought to mind the Purkey & Johnson paper
Antarctica bottom water…(2013) masterfully written where no word seemed wasted. 
Title: Re: What's new in Antarctica ?
Post by: sidd on February 21, 2016, 10:59:12 PM
I think Wili refers to my twisting of the famous aphorism by Voltaire from the passage:

"Mais, monsieur, en étant persuadés par la foi, des choses qui paraissent absurdes à notre intelligence, c'est-à-dire, en croyant ce que nous ne croyons pas, gardons-nous de faire ce sacrifice de notre raison dans la conduite de la vie. Il y a eu des gens qui ont dit autrefois: Vous croyez des choses incompréhensibles, contradictoires, impossibles, parce que nous vous l’avons ordonné; faites donc des choses injustes parce que nous vous l’ordonnons. Ces gens-là raisonnaient à merveille. Certainement qui est en droit de vous rendre absurde est en droit de vous rendre injuste."

(Very) roughly translated,

"But sir, once faith persuades us of things which appear absurd to our intellect, that is to say, into believing what intellect cannot believe, the danger arises of abandoning reason as a governor of our lives. People in the past said to us: You will believe incomprehensible, contradictory and impossible things because we order it; you must do unjust things because we order you. They had marvellous reasoning. Certainly, he who can make you absurd can make you unjust."

This was, of course, an attack on  religion, but Voltaire was nothing if not an acute logician, and touched the heart of the matter in his inimitable style ...
Title: Re: What's new in Antarctica ?
Post by: bligh8 on February 22, 2016, 12:24:35 AM
Thank you Mr. Sidd for your explanation……I point out empathy as it is one of our most enduring qualities that separate us from the beast.

Bligh
Title: Re: What's new in Antarctica ?
Post by: Jim Hunt on March 11, 2016, 01:46:07 PM
A visual image (http://www.esa.int/spaceinimages/Images/2016/03/Ice_cracked) from the recently launched Sentinel 3A satellite:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esa.int%2Fvar%2Fesa%2Fstorage%2Fimages%2Fesa_multimedia%2Fimages%2F2016%2F03%2Fice_cracked%2F15853452-1-eng-GB%2FIce_cracked_node_full_image_2.jpg&hash=822947ce6f883ac8dc6f55e549cb1093)

Quote
One of the first images from Sentinel-3A’s Sea and Land Surface Temperature Radiometer (SLSTR) shows a long crack running through the ice shelf to the east of the centre part of the Antarctic Peninsula. The crack is about 2 km wide, but widens to 4 km or more in some places. There are also finer cracks and structures visible in the ice shelf.
Title: Re: What's new in Antarctica ?
Post by: sidd on March 14, 2016, 11:15:38 PM
DOI: 10.1038/NGEO2675

Nice Antarctic wide study by Alley (not that one) et al. of basal channel melt under ice shelves, tells where the hot water is in detail. They see polynas associated with some, and one disturbing interpretation of Totten.

" ... one [polynya] was in front of the Totten Ice Shelf, in a region with the highest channel density of any ice shelf region ..."

I was kinda hoping that hot water hadn't yet got there. (I inserted the bracketed word "polynya" in the previous quote.)

sidd
Title: Re: What's new in Antarctica ?
Post by: solartim27 on April 21, 2016, 05:06:33 AM
There are some new icebergs from Nansen
http://earthobservatory.nasa.gov/IOTD/view.php?id=87859 (http://earthobservatory.nasa.gov/IOTD/view.php?id=87859)
Nansen broke apart on Apr 8th.  Very considerate to do so before we lost the view to winter.
http://earthobservatory.nasa.gov/IOTD/view.php?id=87657 (http://earthobservatory.nasa.gov/IOTD/view.php?id=87657)

The linked article discusses field work about the influence of tides on Antarctic ice shelves in order to develop better ice shelf/ice sheet models.  I note that the Nansen Ice Shelf is about to break free:

http://phys.org/news/2016-03-nasa-tracking-tides-ice-shelves.html (http://phys.org/news/2016-03-nasa-tracking-tides-ice-shelves.html)

Extract: "he NASA scientists worked with personnel from the Korea Polar Research Institute to install instruments on the Nansen Ice Shelf, a roughly 30-mile-long ice shelf sticking out from the coast of Antarctica's Victoria Land.

Title: Re: What's new in Antarctica ?
Post by: charles_oil on April 25, 2016, 09:46:49 PM
Tourism - busy in the Arctic and Antarctic too !

http://www.bloomberg.com/news/articles/2016-04-25/antarctica-luxury-cruises-world-s-hottest-coldest-tourist-spot (http://www.bloomberg.com/news/articles/2016-04-25/antarctica-luxury-cruises-world-s-hottest-coldest-tourist-spot)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on April 26, 2016, 05:03:18 PM
Robert Scribbler provides a nice update on ice shelf activity in Antarctica focused on the recent major Nansen Ice Shelf calving event:

https://robertscribbler.com/2016/04/25/melt-expanding-into-east-antarctica-as-nansen-ice-shelf-crack-produces-20-kilometer-long-iceberg/

Extract: "Melt Expanding into East Antarctica as Nansen Ice Shelf Crack Produces 20 Kilometer Long Iceberg"
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on April 26, 2016, 06:05:34 PM
Per the linked SciAm article climate change is dramatically changing the penguin populations on the Antarctic Peninsula:

http://www.scientificamerican.com/article/penguin-populations-are-changing-dramatically/ (http://www.scientificamerican.com/article/penguin-populations-are-changing-dramatically/)

Extract: "Penguin Populations Are Changing Dramatically
Rapid warming on the Antarctic Peninsula is killing some species but helping others"
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on April 28, 2016, 05:24:46 PM
A large subglacial lake and canyon system has been identified under the ice in Princess Elizabeth Land in East Antarctica:

http://www.csmonitor.com/Science/2016/0427/Massive-secret-lake-and-canyons-found-deep-beneath-Antarctic-ice (http://www.csmonitor.com/Science/2016/0427/Massive-secret-lake-and-canyons-found-deep-beneath-Antarctic-ice)

Extract: "Scientists, presenting at the European Geosciences Union in Vienna last week, revealed data that indicates the existence of a canyon system beneath Princess Elizabeth Land on the Eastern coast of the continent. The researchers predict that a large subglacial lake runs through that system.
If true, the discovery of the lake could help fill in gaps about one of the most enigmatic areas of Antarctica."
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on April 30, 2016, 12:05:45 AM
The linked article discusses three recent paper about "What lies beneath the ice in West Antarctica":

http://www.sciencecodex.com/what_lies_beneath_west_antarctica-181414 (http://www.sciencecodex.com/what_lies_beneath_west_antarctica-181414)
Title: Re: What's new in Antarctica ?
Post by: charles_oil on May 09, 2016, 02:20:11 AM
Saw part of a news article on moving the Halley research station to avoid falling in a chasm - if you can get it on iPlayer:

http://www.bbc.com/news/36201053 (http://www.bbc.com/news/36201053)

http://www.bbc.co.uk/iplayer/episode/b079s24p/horizon-20152016-8-ice-station-antarctica (http://www.bbc.co.uk/iplayer/episode/b079s24p/horizon-20152016-8-ice-station-antarctica)

Title: Re: What's new in Antarctica ?
Post by: Adam Ash on May 19, 2016, 10:46:34 AM
http://www.nature.com/ngeo/journal/v8/n4/full/ngeo2388.html (http://www.nature.com/ngeo/journal/v8/n4/full/ngeo2388.html)

Ocean access to a cavity beneath Totten Glacier in East Antarctica
'...If thinning trends continue, a larger water body over the trough could potentially allow more warm water into the cavity, which may, eventually, lead to destabilization of the low-lying region between Totten Glacier and the similarly deep glacier flowing into the Reynolds Trough. We estimate that at least 3.5 m of eustatic sea level potential drains through Totten Glacier, so coastal processes in this area could have global consequences.'

Another Antarctic glacier, another discovery of a method of rapid destabilisation and subsequent sea level rise and storm intensity consequences.  Sigh.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on May 27, 2016, 04:47:14 PM
The linked article discusses new research that indicates that the Antarctic Polar Front (see image) is not unbroken and allows seaweed/kelp to float all the way to Antarctica where it can off-load marine species into Antarctic waters where that currently/previously to not exist:

http://theconversation.com/antarctica-may-not-be-as-isolated-as-we-thought-and-thats-a-worry-59969 (http://theconversation.com/antarctica-may-not-be-as-isolated-as-we-thought-and-thats-a-worry-59969)

Extract: "Modelling and oceanographic research has started to indicate that the polar front is not the unbroken, continuous barrier was thought to be. Rather, it is a dynamic, shifting series of water jets that can be breached by features such as eddies, which transport pockets of water through the convergence zone.
New evidence published this month from observations of floating kelp at sea indicates that drifting marine species can cross the polar front and enter Antarctic waters from the north.

Floating kelps act as the “taxi service” of the sea, forming rafts that can transport diverse species – even entire communities – across hundreds of kilometres of open ocean."
Title: Re: What's new in Antarctica ?
Post by: bligh8 on June 03, 2016, 04:14:41 PM
"Floating kelps act as the “taxi service” of the sea, forming rafts that can transport diverse species – even entire communities – across hundreds of kilometres of open ocean."

This I have seen, in a different setting of course. The Gulf Stream with it’s eddies and meanderings form a warm ring which results in unproductive Sargasso Sea water transferred into the productive waters of the continental margin.

In October I’ve seen tropical fish who’s eggs caught in Sargasso kelp drift up against the coast resulting in tropical fish visible within the inlets. 

The apex of the Stream lies several hundred miles South East of this location.
Title: Re: What's new in Antarctica ?
Post by: johnm33 on June 04, 2016, 03:39:06 PM
So whats happening? hat tip to Ben Burch on the blog.
 (https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Farctic.atmos.uiuc.edu%2Fcryosphere%2FIMAGES%2Fseaice.recent.antarctic.png&hash=d413fc2067eace6198996f43dddfd0af)
Title: Re: What's new in Antarctica ?
Post by: Neven on June 04, 2016, 06:28:05 PM
That graph is showing the same faulty data from the malfunctioning sensor. This one from Uni Bremen based on AMSR2 shows a slowdown in ice growth, but I don't know where or why it's taking place (I don't think it's exceptional or anything):
Title: Re: What's new in Antarctica ?
Post by: GeoffBeacon on June 15, 2016, 11:07:52 AM
Is this report in Carbon Brief significant?

Scientists have unearthed a 100m-thick river of ice beneath Antarctica’s Larsen C ice shelf, which they fear could accelerate its path to eventual collapse (http://www.carbonbrief.org/discovery-exposes-fragility-of-antarcticas-larsen-c-ice-shelf).
Title: Re: What's new in Antarctica ?
Post by: Clare on June 15, 2016, 12:21:32 PM
http://www.sciencemag.org/news/2016/06/emergency-rescue-launched-ill-worker-south-pole (http://www.sciencemag.org/news/2016/06/emergency-rescue-launched-ill-worker-south-pole)

"Two propeller-driven planes took off today from Calgary, Canada, on a perilous rescue mission to the U.S. research station at the South Pole. If all goes well, one of the planes will arrive in 6 days to pick up a member of the winter-over crew suffering from an unspecified medical emergency that requires treatment at a hospital.
The Twin Otter aircraft are operated by the Canadian firm Kenn Borek Air, Ltd., which contracts with NSF to provide logistical support to the U.S. Antarctic Program. The aircraft will fly via South America to the British Antarctic Survey’s Rothera Research Station on the Antarctic Peninsula. One will remain there as a backup for search-and-rescue operations; the other will travel another 2400 kilometers to the South Pole."

Currently windchill = -77'C, bleak & DARK.
http://www.usap.gov/videoclipsandmaps/spwebcam.cfm (http://www.usap.gov/videoclipsandmaps/spwebcam.cfm)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on June 15, 2016, 09:59:27 PM
Is this report in Carbon Brief significant?

Scientists have unearthed a 100m-thick river of ice beneath Antarctica’s Larsen C ice shelf, which they fear could accelerate its path to eventual collapse (http://www.carbonbrief.org/discovery-exposes-fragility-of-antarcticas-larsen-c-ice-shelf).

I think that it is potentially significant (in a few decades time with continued global warming), as it indicates that numerous Antarctic ice shelves may become more fragile in the future due to the cumulative affects of repeated surface ice melt and drainage cycles.  I have posted about this in Antarctic Peninsula thread.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on June 16, 2016, 04:43:28 PM
The linked article is entitled: "Antarctic CO2 Hit 400 PPM For First Time in 4 Million Years", see the following extract & attached plot of South Pole CO₂ concentrations through early June 2016.

http://www.climatecentral.org/news/antarctica-co2-400-ppm-million-years-20451 (http://www.climatecentral.org/news/antarctica-co2-400-ppm-million-years-20451)

Extract: "In the remote reaches of Antarctica, the South Pole Observatory carbon dioxide observing station cleared 400 ppm on May 23, according to an announcement from the National Oceanic and Atmospheric Administration on Wednesday. That’s the first time it’s passed that level in 4 million years (no, that’s not a typo)."
Title: Re: What's new in Antarctica ?
Post by: Sigmetnow on June 18, 2016, 03:12:01 AM
A rare, risky mission is underway to rescue sick scientists from the South Pole
https://www.washingtonpost.com/news/speaking-of-science/wp/2016/06/16/a-rare-risky-mission-is-underway-to-rescue-sick-scientists-from-the-south-pole/ (https://www.washingtonpost.com/news/speaking-of-science/wp/2016/06/16/a-rare-risky-mission-is-underway-to-rescue-sick-scientists-from-the-south-pole/)
Title: Re: What's new in Antarctica ?
Post by: Adam Ash on June 20, 2016, 02:08:16 PM
That graph is showing the same faulty data from the malfunctioning sensor. This one from Uni Bremen based on AMSR2 shows a slowdown in ice growth, but I don't know where or why it's taking place (I don't think it's exceptional or anything):

Hi Neven!  I live 2600 km of stormy ocean north of Antarctica. I can assure you we have had an unusually mild winter to date.  Midnight and its 5 degrees C here, when usually we have a lot of snow and ice around and minus 5, not plus.  Fohn winds have melted snow off the tops, and weather forecasts warn of a large sub-topical zone of warm air forming to the west (969hPa in the core) to produce un-seasonally warm weather for the shortest day and beyond. 

My bees are still out gathering nectar and pollen when they would usually be safely in bed munching on their honey stores. The vege garden is still lush green when it would 'normally' (aka 'historically') be a rotting down frozen mess.

So if what I see at 46 south is any indication, its just plain getting warmer.  Climate, that is, not just weather.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on June 29, 2016, 07:18:47 PM
The linked article indicates that penguin populations are projected to be in trouble with continued global warming:


http://www.upi.com/Science_News/2016/06/29/Penguin-population-may-be-halved-by-end-of-century/3961467202270/ (http://www.upi.com/Science_News/2016/06/29/Penguin-population-may-be-halved-by-end-of-century/3961467202270/)


Also see:
http://www.nature.com/articles/srep28785 (http://www.nature.com/articles/srep28785)
Title: Re: What's new in Antarctica ?
Post by: Adam Ash on June 30, 2016, 01:55:06 PM
Right now there is a very fine blast of 70 km/h x 6 degC wind heading directly south from the east coast of Australia almost all the way to the coast of Antarctica just west of the Ross Sea.  This is blocking the seal level circumpolar wind flow (the Roaring 40s) and must be bring a vast amount of energy south.  The following pix from EarthNullSchool show surface, 250hPa (Jetstream) winds and surface temperatures.

I don't recall seeing a block of the Roaring 40s like this before  - usually we in southern New Zealand enjoy a constant progression of low pressure then high pressure cyclonic systems which (used to) bring us the routine sequence of calm-warm with fohn wind-gale and rain - calm and cold weather.  Not any more!
Title: Re: What's new in Antarctica ?
Post by: TerryM on June 30, 2016, 06:36:58 PM
Has this been documented in the past? Is it related to RS's "Gravity Wave" that broke through the equator?
This can't be good.
Terry
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on June 30, 2016, 10:13:58 PM
Per the linked article the Antarctic Ozone Hole is beginning to heal itself:

http://www.sciencemag.org/news/2016/06/ozone-layer-mend-thanks-chemical-ban (http://www.sciencemag.org/news/2016/06/ozone-layer-mend-thanks-chemical-ban)

Title: Re: What's new in Antarctica ?
Post by: Adam Ash on July 01, 2016, 08:38:31 AM
I wonder what this is doing to the circumpolar current?  Everything seems to be conspiring to send it in reverse...

If the circumpolar current slows what does that do to heat transport to the Antarctic glaciers' underbellies?  To sea ice formation and longevity?

(First image shows 'normal' circumpolar current configuration, second shows today's winds which cannot be helping.)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 01, 2016, 04:59:48 PM
I wonder what this is doing to the circumpolar current?  Everything seems to be conspiring to send it in reverse...

If the circumpolar current slows what does that do to heat transport to the Antarctic glaciers' underbellies?  To sea ice formation and longevity?

The conventional thinking is that by itself having the ozone hole heals itself would slow the circumpolar winds around the Southern Ocean; however, increasing GHG concentrations over Antarctica will serve to maintain these winds in the "sweet-spot" that they are currently in for advecting warm CDW toward the grounding lines of key Antarctic marine glaciers.  Furthermore, Hansen's ice-climate positive feedback is also kicking in to promote more marine glacial ice melting and lastly the recently observed transmission of NH Tropical Pacific heat across the equator by a Jetstream directed towards the WAIS may eventually accelerate the date when DeConto & Pollard's hydrofracturing occurs in the WAIS (and the Antarctic Peninsula).

The linked Scribbler article indicates that global warming is flattening the atmospheric slope to the extent that Tropical Pacific atmospheric energy is being directed to Western Antarctica via atmospheric gravity waves.

https://robertscribbler.com/2016/06/28/gigantic-gravity-waves-to-mix-winter-with-summer-wrecked-jet-stream-now-runs-from-pole-to-pole/#comments

Extract: "The upper level air flow that originated near the North Pole joins with a building Southern Hemisphere Jet Stream ridge pattern over the Southeast Pacific. Feeding into very strong upper level winds, it turns southward into a high amplitude wave that crosses the Horn of South America and slams itself, carrying with it a big pulse of extreme warmth, into the upper level airs over Western Antarctica.



All these observations combined point to a very serious concern that Polar warming is flattening the atmospheric slope from Equator to Pole to such an extent that an increasing violation of the Hemisphere to Hemisphere seasonal dividing line may be a new climate change related trend. And that’s a kind of weather weirding that we are not at all really prepared to deal with."
Title: Re: What's new in Antarctica ?
Post by: sidd on July 01, 2016, 08:52:25 PM
ACC has existed since the Drake Passage opened, will not be disrupted so easily ...
Title: Re: What's new in Antarctica ?
Post by: Laurent on July 06, 2016, 09:42:24 PM
Australian Uranium Mining Is Polluting Antarctica Some 6,000 Miles Away
http://www.huffingtonpost.co.uk/entry/australian-uranium-mining-is-polluting-antarctica-some-6000-miles-away_uk_577b8d4ee4b073366f0fb3e5?edition=uk (http://www.huffingtonpost.co.uk/entry/australian-uranium-mining-is-polluting-antarctica-some-6000-miles-away_uk_577b8d4ee4b073366f0fb3e5?edition=uk)
Quote

Scientists have discovered that uranium mining in Australia is polluting the Antarctic, despite being 6,000 nautical miles away from each other.

The damning news comes just a few days after research showed that the enormous ozone hole over Antarctica had in fact started to heal as a result of human action.
Title: Re: What's new in Antarctica ?
Post by: solartim27 on July 10, 2016, 01:15:44 AM
Avoiding the news here in the US, catching up on podcasts I heard this.  15 days left to listen to the stream.
http://www.bbc.co.uk/programmes/p03yptx1 (http://www.bbc.co.uk/programmes/p03yptx1)
Quote
Oldest Antarctic Ice Found
The Science Hour
The importance of analysing the trapped past atmospheres contained in bubbles in ice cores is invaluable to our understanding of our climate. Until now, ice cores drilled in Antarctica only go back to 800,000 years old. But geologists exploring a little known valley, high up in the Trans-Antarctic Mountain chain, have discovered ice that is more than a million years old. And they did not have to use expensive drills to get it, just a shovel! The ice was under a thin layer of debris, pushed up from the deep.

Title: Re: What's new in Antarctica ?
Post by: Adam Ash on July 14, 2016, 11:15:32 AM
Has anybody estimated what the effect on sea level rise will be from the resulting isostatic rebound? 

Assuming it all rebounds to near or above present-day sea level, that displacement would add several metres more to the current maximum estimated sea level rise.  Both Antarctica and Greenland have massive ice overburden on top of land held below sea level which will no doubt rise (and hence displace ocean) when the load is removed.
Title: Re: What's new in Antarctica ?
Post by: Laurent on July 14, 2016, 11:40:58 AM
What some centimetres of that plate would do to sea level... https://en.wikipedia.org/wiki/Antarctic_Plate 11% of earth surface ?...
Title: Re: What's new in Antarctica ?
Post by: folke_kelm on July 14, 2016, 02:54:43 PM
Adam Ash,

Since isostatic rebound is a question of geology i may answer because just that is my profession.
You have always  to consider that isostatic rebound is a complex movement of the plate and its surroundings. While Antarctica itself is depressed into the deeper layers, this material is squeezed aside and lifts up the surrounding plates without ice cap.
Due to the fact that Antarctica is surrounded by oceanic crust  this crust will sink as a reaction of the isostatic rebound of Antarctica. This will counteract a potential sea level rise due to a rebounding antarctic plate.

Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 14, 2016, 08:05:32 PM
Has anybody estimated what the effect on sea level rise will be from the resulting isostatic rebound? 

Assuming it all rebounds to near or above present-day sea level, that displacement would add several metres more to the current maximum estimated sea level rise.  Both Antarctica and Greenland have massive ice overburden on top of land held below sea level which will no doubt rise (and hence displace ocean) when the load is removed.

The following reference indicates that after GIA correction the Amundsen Sea sector is contributing more to SLR than model GRACE measurements indicate, possibly by as much as 40%:

An investigation of Glacial Isostatic Adjustment over the Amundsen Sea sector, West Antarctica
by: A. Groh; H. Ewert, M. Scheinert, M. Fritsche, A. Rülke, A. Richter, R. Rosenau, R. Dietrich
http://dx.doi.org/10.1016/j.gloplacha.2012.08.001 (http://dx.doi.org/10.1016/j.gloplacha.2012.08.001)

Abstract
The present study focuses on the Amundsen Sea sector which is the most dynamical region of the Antarctic Ice Sheet (AIS). Based on basin estimates of mass changes observed by the Gravity Recovery and Climate Experiment (GRACE) and volume changes observed by the Ice, Cloud and Land Elevation Satellite (ICESat), the mean mass change induced by Glacial Isostatic Adjustment (GIA) is derived. This mean GIA-induced mass change is found to be 34.1 ± 11.9 Gt/yr, which is significantly larger than the predictions of current GIA models. We show that the corresponding mean elevation change of 23.3 ± 7.7 mm/yr in the Amundsen Sea sector is in good agreement with the uplift rates obtained from observations at three GPS sites. Utilising ICESat observations, the observed uplift rates were corrected for elastic deformations due to present-day ice-mass changes. Based on the GRACE-derived mass change estimate and the inferred GIA correction, we inferred a present-day ice-mass loss of − 98.9 ± 13.7 Gt/yr for the Amundsen Sea sector. This is equivalent to a global eustatic sea-level rise of 0.27 ± 0.04 mm/yr. Compared to the results relying on GIA model predictions, this corresponds to an increase of the ice-mass loss or sea-level rise, respectively, of about 40%.
Title: Re: What's new in Antarctica ?
Post by: sidd on July 14, 2016, 09:41:33 PM
Nice paper on CDW melt on Antarctic Peninsula, showing melt of southern glaciers due to warming at depth.

DOI: 10.1126/science.aae0017

 I attach fig 1.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 29, 2016, 07:44:44 PM
The atmospheric CO₂ concentration has now passed the 400ppm mark:

http://www.envirotech-online.com/news/environmental-laboratory/7/breaking_news/antarctic_carbon_dioxide_concentration_hits_440ppm_for_first_time_in_four_million_years/39743/ (http://www.envirotech-online.com/news/environmental-laboratory/7/breaking_news/antarctic_carbon_dioxide_concentration_hits_440ppm_for_first_time_in_four_million_years/39743/)

Extract: "On May 23rd, the continent of Antarctica finally surpassed the 400PPM mark, making it the last region on Earth to succumb to our relentless pollution of the atmosphere. It’s the first time that the continent has witnessed such high levels of CO2 in at least four million years."
Title: Re: What's new in Antarctica ?
Post by: FishOutofWater on July 30, 2016, 07:46:16 PM
Remember that isostatic rebound is a slow process that is still going on from the last glacial period more than 10,000 years ago.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on August 02, 2016, 03:30:18 AM
Remember that isostatic rebound is a slow process that is still going on from the last glacial period more than 10,000 years ago.

You should remember from school, that isostatic rebound from current ice mass loss is associated with two processes, with the first due to elastic rebound (related you Young's Modulus) which happens immediately after the ice mass is lost (only the second process is slow due to magma migration).
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on August 09, 2016, 12:18:53 AM
The Polar Meteorology Group has some interesting research going on:

http://bpcrc.osu.edu/groups/polar-meteorology-group (http://bpcrc.osu.edu/groups/polar-meteorology-group)
http://polarmet.osu.edu/ (http://polarmet.osu.edu/)

Title: Re: What's new in Antarctica ?
Post by: sidd on August 09, 2016, 05:36:12 AM
bprc.osu.edu is the Byrd Polar research centre, one of my favorite places. The great Lonnie Thompson, his wife Ellen-Mosely who is a formidable researcher also, Ian Howat, Leonid Polyak and many others. Mercer was from there also, more recently Box and Enderlin who have moved on.

In misty days of yore, I stole ... borrowed ... equipment and facilities from and supplied some to them as well. They have accumulated one of the largest ice core archives under the Thompsons and many others.

Nice place. Check em out on the web, or if you are in Columbus, in person. They frequently have talks which are always worth attending, most are streamed on the net.

sidd
Title: Re: What's new in Antarctica ?
Post by: FishOutofWater on August 09, 2016, 02:56:17 PM
Large volumes of magma are not moving around eastern Canada and Scandinavia.

Isostatic adjustment occurs by mantle creep. At the high temperatures of the upper mantle the rock undergoes plastic deformation. Because the effective viscosity of solid ultramafic rock is very high, isostatic adjustment is very slow.

http://gji.oxfordjournals.org/content/157/3/1297.full (http://gji.oxfordjournals.org/content/157/3/1297.full)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on August 09, 2016, 06:35:24 PM
Large volumes of magma are not moving around eastern Canada and Scandinavia.

Isostatic adjustment occurs by mantle creep. At the high temperatures of the upper mantle the rock undergoes plastic deformation. Because the effective viscosity of solid ultramafic rock is very high, isostatic adjustment is very slow.

http://gji.oxfordjournals.org/content/157/3/1297.full (http://gji.oxfordjournals.org/content/157/3/1297.full)

FishOutofWater,
Thanks for the useful/relevant information about isostatic rebound in Northern Latitudes; however, as the following re-posted information indicates the tectonic behavior in the WAIS is more complex as the mantle below the Byrd Subglacial Basin (BSB) and Marie Byrd Land has magma with very low viscosity, as discussed in the two re-posted Replies from the Antarctic Tectonic thread (also the rate of ice mass loss from the BSB is exceptionally high).

Best,
ASLR

The following abstract comes from the International Glacial Society Proceeding 65 at the following link:

http://www.igsoc.org/symposia/2014/chamonix/proceedings/procsfiles/procabstracts_65.htm (http://www.igsoc.org/symposia/2014/chamonix/proceedings/procsfiles/procabstracts_65.htm)

It is particularly interesting that Wilson et al 2014 indicate that the magma beneath Marie Byrd Land has very low viscosity:

70A1149
The POLENET-ANET integrated GPS and seismology approach to understanding glacial isostatic adjustment and ice mass change in Antarctica

Terry WILSON, Michael BEVIS, Stephanie KONFAL, Richard ASTER, Julien CHAPUT, David HEESZEL, Douglas WIENS, Sridhar ANANDAKRISHNAN, Ian DALZIEL, Audrey HUERTA, Eric KENDRICK
Corresponding author: Terry Wilson
Corresponding author e-mail: wilson.43@osu.edu

Abstract: "The POLENET-ANET project is simultaneously resolving crustal motions, measured by GPS, and Earth structure and rheological properties, mapped by seismology. Measured vertical and horizontal crustal motion patterns are not explained by extant glacial isostatic adjustment (GIA) models. These models have ice histories dominated by ice loss following the Last Glacial Maximum (LGM) and rely on 1-D Earth models, with rheological properties varying only radially. Seismological results from POLENET-ANET are revealing significant complexity in lateral variation in Earth properties. For example, crustal thickness variations occur not only across the East-West Antarctic boundary, but also between crustal blocks within West Antarctica. Modeling of mantle viscosity based on shear wave velocities shows a sharp lateral gradient from high to low viscosity in the Ross Embayment, a much more gradual gradient in the Weddell Embayment, and very low viscosities below Marie Byrd Land and the Amundsen Sea Embayment (ASE). Remarkable vertical and horizontal bedrock crustal motion velocity magnitudes, directions and patterns correlate spatially, in many aspects, with Earth property variations mapped by seismology. Within the ASE, extremely high upward velocities are flanked by subsiding regions – neither predicted by GIA models. Given the thin crust and low mantle viscosity, it is likely that this is not an LGM signal, which would have already relaxed, and uplift due to the elastic response to modern ice mass change clearly is important. As in other regions where rapid GIA-induced uplift has been measured, the crustal velocities in the Amundsen Embayment may also record a viscoelastic response to ice loss on decadal–centennial timescales. Along the East-West Antarctic boundary in the Ross Embayment, GIA-induced horizontal crustal motions are toward rather than away from the principal ice load center, correlating spatially with the strong lateral gradient in mantle viscosity. In the Weddell Embayment region, where crustal thickness is intermediate between East and West Antarctica and mantle viscosity values are moderate, crustal motions show the best match with predictions of GIA models. It is clear that lateral variations in Earth properties fundamentally control the isostatic response to ice mass changes in Antarctica. Ongoing integrated seismic-GPS studies are critical to developing the next generation of GIA models."

Also see:
The following linked reference cites evidence of low upper mantle velocities inland of the Amundsen Sea.  Such low-velocity zones indicate the presence of a significant degree of partial melting, and thus to potential for rapid rebound when ice mass is lost from the Byrd Subglacial Basin:

Natalie J. Accardo, Douglas A. Wiens, Stephen Hernandez, Richard C. Aster, Andrew Nyblade, Audrey Huerta, Sridhar Anandakrishnan, Terry Wilson, David S. Heeszel and Ian W. D. Dalziel, (2014), "Upper mantle seismic anisotropy beneath the West Antarctic Rift System and surrounding region from shear wave splitting analysis", Geophys. J. Int. (2014) doi: 10.1093/gji/ggu117

http://gji.oxfordjournals.org/content/early/2014/05/21/gji.ggu117.abstract (http://gji.oxfordjournals.org/content/early/2014/05/21/gji.ggu117.abstract)

Abstract: "We constrain azimuthal anisotropy in the West Antarctic upper mantle using shear wave splitting parameters obtained from teleseismic SKS, SKKS and PKS phases recorded at 37 broad-band seismometres deployed by the POLENET/ANET project. We use an eigenvalue technique to linearize the rotated and shifted shear wave horizontal particle motions and determine the fast direction and delay time for each arrival. High-quality measurements are stacked to determine the best fitting splitting parameters for each station. Overall, fast anisotropic directions are oriented at large angles to the direction of Antarctic absolute plate motion in both hotspot and no-net-rotation frameworks, showing that the anisotropy does not result from shear due to plate motion over the mantle. Further, the West Antarctic directions are substantially different from those of East Antarctica, indicating that anisotropy across the continent reflects multiple mantle regimes. We suggest that the observed anisotropy along the central Transantarctic Mountains (TAM) and adjacent West Antarctic Rift System (WARS), one of the largest zones of extended continental crust on Earth, results from asthenospheric mantle strain associated with the final pulse of western WARS extension in the late Miocene. Strong and consistent anisotropy throughout the WARS indicate fast axes subparallel to the inferred extension direction, a result unlike reports from the East African rift system and rifts within the Basin and Range, which show much greater variation. We contend that ductile shearing rather than magmatic intrusion may have been the controlling mechanism for accumulation and retention of such coherent, widespread anisotropic fabric. Splitting beneath the Marie Byrd Land Dome (MBL) is weaker than that observed elsewhere within the WARS, but shows a consistent fast direction, possibly representative of anisotropy that has been ‘frozen-in’ to remnant thicker lithosphere. Fast directions observed inland from the Amundsen Sea appear to be radial to the dome and may indicate radial horizontal mantle flow associated with an MBL plume head and low upper mantle velocities in this region, or alternatively to lithospheric features associated with the complex Cenozoic tectonics at the far-eastern end of the WARS."
Title: Re: What's new in Antarctica ?
Post by: FishOutofWater on August 09, 2016, 08:19:28 PM
Very interesting papers about rebound in Antarctica. If rebound can happen quickly there because of large scale magma movement towards the region of ice loss then the whole process of deglaciation and sea level rise may speed up. It's a good problem for folks testing numerical models.

Then there's the possibility of increased volcanic activity caused by decompression melting of upper mantle and lower crustal rock.

I had no idea that Antarctica had rapid rebound. Low silica magmas have low viscosity so we can guess that the magma composition is basaltic to ultramafic.  Hmmm....

Thanks. There's a lot to think about.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on August 09, 2016, 09:08:54 PM
Very interesting papers about rebound in Antarctica. If rebound can happen quickly there because of large scale magma movement towards the region of ice loss then the whole process of deglaciation and sea level rise may speed up. It's a good problem for folks testing numerical models.

Then there's the possibility of increased volcanic activity caused by decompression melting of upper mantle and lower crustal rock.

I had no idea that Antarctica had rapid rebound. Low silica magmas have low viscosity so we can guess that the magma composition is basaltic to ultramafic.  Hmmm....

Thanks. There's a lot to think about.

The linked thread on Antarctic Tectonics addresses many of the issues that you raise:

http://forum.arctic-sea-ice.net/index.php/topic,393.0.html (http://forum.arctic-sea-ice.net/index.php/topic,393.0.html)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on August 24, 2016, 11:36:35 PM
The linked article discusses how one Antarctic ice core was obtained & transported to the USA:

http://arstechnica.com/science/2016/08/from-the-south-pole-to-the-science-section-how-ice-becomes-knowledge/ (http://arstechnica.com/science/2016/08/from-the-south-pole-to-the-science-section-how-ice-becomes-knowledge/)

Extract: "The newest specimen in the Antarctic collection is the US-National-Science-Foundation-funded South Pole ice (SPICE) core, a 1,750-meter-long stick of ice drilled just a few kilometers from the permanent Amundsen-Scott South Pole Station. Obtaining it took two two-month campaigns.
One of the most distinctive aspects of this core is that it will contain a record of extremely trace gases. University of Washington researcher TJ Fudge explained to Ars, “If we’re thinking about carbon dioxide, that’s measured in parts per million. If we’re thinking about methane, that’s measured in parts per billion. This core is going to be good for measuring COS [carbonyl sulfide]; that’s measured in parts per trillion.”
“The reason this is a good site for it is that it has a unique combination of being very cold, because it’s so far [south] at the pole, yet it has a relatively high snowfall because it gets moisture [traveling] from the West Antarctic side over to the East Antarctic side,” he continued. Higher snowfall means thicker annual layers of ice, so you can make measurements at higher resolution—even if you need a fair number of trapped bubbles of gas to make your delicate measurement. Since the South Pole is so isolated even by Antarctic standards, the ice contains little in the way of impurities that make measuring trace chemicals difficult.

The other key piece of information is the evidence of volcanic eruptions marked by sulfate (and occasionally ash) in the core. “What’s nice about the South Pole,” Erich Osterberg said, “is that we’ve got this southern polar vortex—you can almost think about it like this big drain in the atmosphere, or this big whirlpool—and all the [volcanic material] that’s up in the stratosphere gets funneled down and focused into the middle of Antarctica. So at the South Pole, we think that we will get to see a more clean picture of what’s happening for volcanic eruptions around the world.”
That’s interesting in its own right, as large eruptions have short-term impacts on climate worth studying. But it’s also extremely useful for nailing down the timeline of the ice core. The fallout from an eruption will show up in that year’s ice in many cores, so this provides a firm marker you can use to tie all the timelines together. That adds an independent check on your annual layer count, and at depths in the core where annual layers become too thin to pick apart, it sets known points to work between.
“That’s a big part of what we’re doing, because the whole science community that is gonna use this ice core, they need that timescale. All the science is really constrained by how good the timescale is,” Osterberg said. “If we want to do analyses, or start to understand what’s forcing the climate, how the climate is responding, if you don’t know exactly when these [things] are happening you can’t compare to other records, you can’t compare to other ice cores, you can’t compare to the records from the ocean telling us what the ocean is doing.”
Once ages are assigned to every point along the ice core, the rest of the science can begin. That includes examining the temperatures recorded by isotopes of oxygen and hydrogen, as well as greenhouse gas concentrations. But the South Pole ice core will make other, more distinct contributions.
First, it will provide pristine records of trace gases like carbonyl sulfide [COS], carbon monoxide, and methyl chloride. “The thing about COS, unlike CO2, is that it isn’t respired by plants,” TJ Fudge said. “It’s taken up by plants, but it isn’t respired by plants. So looking at changes in COS through time has the potential to tell us about global biological production—essentially, what are the plant life changes that occur through these climate changes?”
Carbon monoxide plays a significant role in the network of reactions that eats up gases like methane (converting it to CO2), but we don’t understand the natural sources of carbon monoxide nearly as well as we do other gases. Getting a long-term record of carbon monoxide behavior will help put its recent behavior in context, allowing scientists to better tease apart human impacts. And methyl chloride helps researchers finger the sources responsible for changes in methane concentrations. It’s also one of the compounds that naturally destroys ozone, so changes in methyl chloride shift the balance of ozone chemistry.

As it happens, there is also a record of phytoplankton growth trapped in this ice core. Phytoplankton produce dimethyl sulfide, an organic sulfur compound that drifts into the atmosphere where it contributes to cloud formation. Some of that dimethyl sulfide ends up in the Antarctic ice in the form of methanesulfonic acid (MSA). So when phytoplankton productivity goes up, the amount of MSA in the South Pole ice core should show it.
“So we’re actually able to look at both of those hypotheses. Do we see evidence that there would be more biological activity? And do we see evidence that just the winds themselves may have increased mixing and changed CO2?” Osterberg said.
There’s plenty more, like using an isotope of beryllium to track historic solar activity or an isotope of krypton to investigate local atmospheric pressure variability. "
Title: Re: What's new in Antarctica ?
Post by: budmantis on August 25, 2016, 02:25:27 AM
Enjoyed reading your post ASLR. I'd be curious to know how many years this ice core will span.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on August 25, 2016, 02:51:19 AM
Enjoyed reading your post ASLR. I'd be curious to know how many years this ice core will span.

It spans well over the past 40,000 years, and you can read about all the details about the SPICE program at the following link:

http://spicecore.org/ (http://spicecore.org/)
Title: Re: What's new in Antarctica ?
Post by: budmantis on August 25, 2016, 03:06:15 AM
Thanks!
Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on September 03, 2016, 09:42:51 PM
Couple of days of big drops in extent? First of the spring storms?
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on September 04, 2016, 12:10:18 AM
Couple of days of big drops in extent? First of the spring storms?

The linked article indicates that storm-force winds have flipped winter to summer conditions in West Antarctica:

https://robertscribbler.com/2016/09/02/warm-storm-force-winds-blowing-up-from-the-equator-change-west-antarctic-winter-to-summer/

Extract: "Warm, Storm-Force Winds Blowing From the Equator Flip West Antarctic Winter to Summer"

Title: Re: What's new in Antarctica ?
Post by: Buddy on September 15, 2016, 06:26:39 PM
Quote
Extract: "Warm, Storm-Force Winds Blowing From the Equator Flip West Antarctic Winter to Summer"

I'll say.  Looks like southern winter maximum came about 3 weeks early.....around August 22nd or so.  And then the ice extent has made an initial sharp move lower since then.

Looks like the earliest max in quite a while.....
Title: Re: What's new in Antarctica ?
Post by: Stephen on September 18, 2016, 12:27:30 PM
Quote
Extract: "Warm, Storm-Force Winds Blowing From the Equator Flip West Antarctic Winter to Summer"

I'll say.  Looks like southern winter maximum came about 3 weeks early.....around August 22nd or so.  And then the ice extent has made an initial sharp move lower since then.

Looks like the earliest max in quite a while.....

Have a look at the NSIDC extent graph for 2015. there was a similar, but smaller decline at this time, but then a steep increase from day 269 to 277
Title: abc australia article about antarctic sea ice plunge
Post by: sqwazw on September 21, 2016, 12:28:44 PM
Anecdotal thinning shelves near Mawson and Davis in Antarctica:

http://www.abc.net.au/news/2016-09-21/sea-ice-record-retreat-has-antarctic-experts-worried/7865732 (http://www.abc.net.au/news/2016-09-21/sea-ice-record-retreat-has-antarctic-experts-worried/7865732)

Quote
"Often the first voyage of the season is quite challenging getting close to Davis [station] so from a long way out we'll encounter ice some [160 to 320 kilometres] and that can be hard to get through," he said.

"With any luck that ability to get closer to the station will be easier.

"But it could be we don't have good enough ice beside the station in which to park the ship and unload our cargo onto the ice."

He said equipment may have to be dismantled and flown in to bases like Davis.

"We can use our helicopters to get our equipment and people onshore if the ice isn't good enough to drive on, however obviously we can't get our heavy equipment to shore in that case," Mr Clifton said.

Earlier this week a vehicle travelling outside Mawson station broke through a thin section of sea ice, but no one was hurt.
Title: Re: What's new in Antarctica ?
Post by: solartim27 on October 25, 2016, 07:17:01 PM
Colorized version of the film of Scott's expedition:
http://boingboing.net/2016/10/25/colorized-film-and-photos-of-a.html (http://boingboing.net/2016/10/25/colorized-film-and-photos-of-a.html)
Quote
In 1912, Herbert Ponting captured remarkable film and images of Captain Robert Falcon Scott's ill-fated Terra Nova Expedition. Amateurs and pros have all worked to restore and colorize Ponting's work.

Via the preservationists at BFI:

    The Great White Silence is one of the jewels in the crown of the BFI National Archive fully justifying this stunning tinted and toned restoration with new score by electronic musician Simon Fisher Turner. The official film record of the British Expedition of 1910-13 led by Scott was reworked by photographer Herbert Ponting to tell the tragic tale but It is the beauty of the images of Antarctica’s frozen landscapes in this film that linger.

Bonus: Interesting mini-doc on how they chose the scoring:  (viewable on website, includes quite a few bits of the movie)
The film also shows the "making-of" reverse of Ponting's stunning still, colorized by Imgurian ktrcoyote http://imgur.com/06LqCsG (http://imgur.com/06LqCsG):
Title: Re: What's new in Antarctica ?
Post by: solartim27 on October 25, 2016, 11:36:30 PM
I am sad to report the death of researcher Gordon Hamilton this weekend in an accident while working in Antarctica.

http://www.pri.org/stories/2016-10-25/us-climate-scientist-killed-antarctica-accident (http://www.pri.org/stories/2016-10-25/us-climate-scientist-killed-antarctica-accident)

http://www.nytimes.com/2016/10/25/science/gordon-hamilton.html?smid=tw-nytimesscience&smtyp=cur&_r=0 (http://www.nytimes.com/2016/10/25/science/gordon-hamilton.html?smid=tw-nytimesscience&smtyp=cur&_r=0)
Quote
The helicopter hovered 30 feet above a fjord in Greenland, a thrumming red speck of human ingenuity in a vast wilderness of rock and ice.

Gordon Hamilton leaned out the right side at a crazy angle, dropping a scientific instrument into the water below. He wore a seatbelt for safety, but he looked as if he might break free at any moment and plunge into the icy water.

He must have seen the worried look on my face, and he shot me a big grin. That moment, that smile: That is how I will always remember him, a man willing to court danger to do the job he loved.

Gordon Stuart Hamilton, 50, a glaciologist at the University of Maine, was killed over the weekend on a scientific expedition to Antarctica. He was surveying a trail to find the crevasses that can make working on glacial ice so dangerous, and his snowmobile plunged into one of them.

http://www.nytimes.com/2016/10/25/science/gordon-hamilton-climate-scientist-dies-accident-antarctica.html?action=click&contentCollection=Science&module=RelatedCoverage&region=Marginalia&pgtype=article (http://www.nytimes.com/2016/10/25/science/gordon-hamilton-climate-scientist-dies-accident-antarctica.html?action=click&contentCollection=Science&module=RelatedCoverage&region=Marginalia&pgtype=article)
Quote
Gordon Hamilton, a prominent climate scientist who studied glaciers and their impact on sea levels in a warming climate, died on Saturday in Antarctica when the snowmobile he was riding plunged into a 100-foot-deep crevasse. He was 50.

The National Science Foundation, which was funding his research, reported the death. The episode is under investigation, officials said.

Dr. Hamilton died on White Island in the continent’s Ross Archipelago, according to the University of Maine, in Orono, where he was an associate research professor in the glaciology group at the Climate Change Institute.
...
When not in the field, he taught undergraduate and graduate students at the University of Maine. He was also involved in statewide initiatives aimed at high school-age children.

Before joining the university’s Climate Change Institute as an assistant research professor in 2000, Dr. Hamilton worked at the Byrd Polar and Climate Research Center at Ohio State University and at the Norwegian Polar Institute, according to the National Science Foundation.

He is survived by his wife, Fiona, and two children, Martin and Calum.
Title: Re: What's new in Antarctica ?
Post by: Sleepy on October 26, 2016, 06:45:36 AM
Thanks solartim, not one single line about Hamilton here.
Title: Re: What's new in Antarctica ?
Post by: Tigertown on October 27, 2016, 05:52:02 AM
Article about Antarctic Ice melting faster and from below.

www.npr.org/sections/thetwo-way/2016/10/25/499206005/antarcticas-ice-sheets-are-melting-faster-and-from-beneath (http://www.npr.org/sections/thetwo-way/2016/10/25/499206005/antarcticas-ice-sheets-are-melting-faster-and-from-beneath)
Title: Re: What's new in Antarctica ?
Post by: jai mitchell on October 27, 2016, 07:24:06 PM
here is the article and a very very important graphic, note the elevation changes per year.

article here:  http://www.nature.com/articles/ncomms13243 (http://www.nature.com/articles/ncomms13243)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.nature.com%2Farticle-assets%2Fnpg%2Fncomms%2F2016%2F161025%2Fncomms13243%2Fimages%2Fw926%2Fncomms13243-f1.jpg&hash=571748899855a4b57b8e148a1ffbddfd)
Title: Re: What's new in Antarctica ?
Post by: Tigertown on October 27, 2016, 08:12:37 PM
Just read that Smith's, Pine Island, and Thwaites Glaciers are all on retro-grade slopes away from the grounding lines.When warm water circulates under the ice shelf, it gets under the ice and flows downhill inland, melting away at these from underneath.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on October 28, 2016, 05:48:30 PM
The linked article is entitled: "Space Weather from a Southern Point of View".  It indicates that Antarctic provides a unique vantage point for viewing near-Earth space:

https://eos.org/project-updates/space-weather-from-a-southern-point-of-view?utm_source=eos&utm_medium=email&utm_campaign=EosBuzz102816

Extract: "A recently completed instrument array in Antarctica provides a more complete understanding of the near-Earth space environment."
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on October 30, 2016, 11:55:15 PM
The linked reference is entitled: "Resonance vibrations of the Ross Ice Shelf and observations of persistent atmospheric waves":

Oleg A. Godin & Nikolay A. Zabotin (10 October 2016), "Resonance vibrations of the Ross Ice Shelf and observations of persistent atmospheric waves", JGR Space Physics, DOI: 10.1002/2016JA023226


http://onlinelibrary.wiley.com/doi/10.1002/2016JA023226/abstract (http://onlinelibrary.wiley.com/doi/10.1002/2016JA023226/abstract)

Abstract: "Recently reported lidar observations have revealed a persistent wave activity in the Antarctic middle and upper atmosphere that has no counterpart in observations at midlatitude and low-latitude locations. The unusual wave activity suggests a geographically specific source of atmospheric waves with periods of 3–10 h. Here we investigate theoretically the hypothesis that the unusual atmospheric wave activity in Antarctica is generated by the fundamental and low-order modes of vibrations of the Ross Ice Shelf (RIS). Simple models are developed to describe basic physical properties of resonant vibrations of large ice shelves and their coupling to the atmosphere. Dispersion relation of the long surface waves, which propagate in the floating ice sheet and are responsible for its low-order resonances, is found to be similar to the dispersion relation of infragravity waves in the ice-free ocean. The phase speed of the surface waves and the resonant frequencies determine the periods and wave vectors of atmospheric waves that are generated by the RIS resonant oscillations. The altitude-dependent vertical wavelengths and the periods of the acoustic-gravity waves in the atmosphere are shown to be sensitive to the physical parameters of the RIS, which can be difficult to measure by other means. Predicted properties of the atmospheric waves prove to be in a remarkable agreement with the key features of the observed persistent wave activity."

See also the associate article entitled: "Weird 'Gravity' Waves Above Antarctica Caused by Ice Vibrations":

http://www.livescience.com/56686-ice-vibrations-cause-weird-waves-above-antarctica.html (http://www.livescience.com/56686-ice-vibrations-cause-weird-waves-above-antarctica.html)
Title: Re: What's new in Antarctica ?
Post by: Sigmetnow on November 03, 2016, 12:30:35 PM
Photos from this year's NASA Operation IceBridge mission over Antarctica.
http://www.nbcnews.com/slideshow/fly-over-country-stunning-aerial-views-antarctica-n676866 (http://www.nbcnews.com/slideshow/fly-over-country-stunning-aerial-views-antarctica-n676866)
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on November 05, 2016, 04:41:24 PM
Photos from this year's NASA Operation IceBridge mission over Antarctica.
http://www.nbcnews.com/slideshow/fly-over-country-stunning-aerial-views-antarctica-n676866 (http://www.nbcnews.com/slideshow/fly-over-country-stunning-aerial-views-antarctica-n676866)

Also the linked website offers some more stunning photos of Antarctica from NASA's IceBridge flights:

http://news.nationalgeographic.com/2016/11/nasa-ice-bridge/ (http://news.nationalgeographic.com/2016/11/nasa-ice-bridge/)

Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on November 14, 2016, 02:42:49 PM
http://www.nature.com/articles/ncomms13243 (http://www.nature.com/articles/ncomms13243)

Getting twitchy about this now. I had been keeping up to the travels of warmed bottom waters as they broke through the circumpolars ( whist they were being augmented by the Ozone hole ) and headed around the continent finally reaching Ross in 2012.

Now the Ozone hole is showing some recovery and the Pacific forcings supposedly reversed in 2014 meaning the losses, noted above, will now rapidly increase.
Title: Re: What's new in Antarctica ?
Post by: Tigertown on November 14, 2016, 06:28:10 PM
I have been reading for a while now about the crack in Larson C ,but this is the newest info that I can find.

www.climatecentral.org/news/rift-speeds-up-across-antarctic-ice-shelf-20752 (http://www.climatecentral.org/news/rift-speeds-up-across-antarctic-ice-shelf-20752)

Anyone runs across any updates, please share, as this will be a huge iceberg, when it breaks off.
Title: Re: What's new in Antarctica ?
Post by: Sleepy on November 14, 2016, 06:46:49 PM
Tigertown, there's a dedicated thread on Larsen C here:
http://forum.arctic-sea-ice.net/index.php/topic,1175.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1175.0.html)
Title: Re: What's new in Antarctica ?
Post by: Tigertown on November 14, 2016, 08:46:55 PM
Tigertown, there's a dedicated thread on Larsen C here:
http://forum.arctic-sea-ice.net/index.php/topic,1175.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1175.0.html)

Thanks. I will follow henceforth.
Title: Re: What's new in Antarctica ?
Post by: CalamityCountdown on November 16, 2016, 03:54:07 AM
Mysterious Winds Cause Rapid Melting of Antarctic Ice
http://news.nationalgeographic.com/2016/11/foehn-winds-melt-ice-shelves-antarctic-peninsula-larsen-c/ (http://news.nationalgeographic.com/2016/11/foehn-winds-melt-ice-shelves-antarctic-peninsula-larsen-c/)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on November 16, 2016, 06:56:27 AM
That was a good article.  Here's a gif of the area above Larsen B from Nov 10 to 15.  Looking pretty blue.  Remarkable how fast the sea ice can scurry away.
Title: Re: What's new in Antarctica ?
Post by: oren on November 17, 2016, 09:37:40 PM
Mysterious Winds Cause Rapid Melting of Antarctic Ice
http://news.nationalgeographic.com/2016/11/foehn-winds-melt-ice-shelves-antarctic-peninsula-larsen-c/ (http://news.nationalgeographic.com/2016/11/foehn-winds-melt-ice-shelves-antarctic-peninsula-larsen-c/)
Very interesting, and disturbing.
Title: Re: What's new in Antarctica ?
Post by: Andre on November 19, 2016, 04:20:15 AM
Not sure if this has been posted already:

RIMS 2016: Sea Level Rise Will Be Worse and Come Sooner
http://www.insurancejournal.com/news/national/2016/04/12/405089.htm (http://www.insurancejournal.com/news/national/2016/04/12/405089.htm)

Abstract:
"Think sea level rise will be moderate and something we can all plan for? Think again.

Sea levels could rise by much more than originally anticipated, and much faster, according to new data being collected by scientists studying the melting West Antarctic ice sheet – a massive sheet the size of Mexico."
Title: Re: What's new in Antarctica ?
Post by: Tigertown on November 19, 2016, 04:31:45 AM
Good article, but failed to mention the geothermal activity under the W. Antarctica ice sheet. That could move the calendar up a bit.
Title: Re: What's new in Antarctica ?
Post by: oren on November 19, 2016, 02:06:00 PM
This talk has been mentioned before (note this is from April) but I believe the article itself was not. I wonder when these OMG findings might be made public.
Title: Re: What's new in Antarctica ?
Post by: Csnavywx on November 21, 2016, 01:04:01 AM
The "OMG findings" were her personal opinion (as per corrective e-mail to Eric Holtaus earlier this year). Worst case is 1m by 2050 atm (per the Hansen paper), which would cause plenty of issues on its own.
Title: Re: What's new in Antarctica ?
Post by: charles_oil on November 23, 2016, 09:55:05 PM
New article on the BBC news service:

Huge glacier retreat triggered in 1940s
By Jonathan Amos
BBC Science Correspondent

http://www.bbc.com/news/science-environment-38079838 (http://www.bbc.com/news/science-environment-38079838)

The melting Antarctic glacier that now contributes more to sea-level rise than any other ice stream on the planet began its big decline in the 1940s.
This is when warm ocean water likely first got under Pine Island Glacier (PIG) to loosen the secure footing it had enjoyed up until that point.
Researchers figured out the timing by dating the sediments beneath the PIG.
It puts the glacier’s current changes in their proper historical context, the scientists tell Nature magazine.

## When you go to the BBC article - and click on the ....tell Nature Magazine part, it takes you to the article in full (but un-downloadable).
Title: Re: What's new in Antarctica ?
Post by: Tigertown on November 29, 2016, 12:07:22 AM
Not my discovery, but a melt pond in the Mcmurdo Sound area.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on November 29, 2016, 10:44:13 AM
http://www.sciencealert.com/the-west-antarctic-ice-shelf-is-breaking-up-from-the-inside-researchers-find (http://www.sciencealert.com/the-west-antarctic-ice-shelf-is-breaking-up-from-the-inside-researchers-find)

More news on P.I.G. (and its upcoming collapse?)
Title: Re: What's new in Antarctica ?
Post by: Buddy on November 29, 2016, 12:42:16 PM
Quote
More news on P.I.G. (and its upcoming collapse?)

Day by day.....week by week....and month by month, mother earth is screaming at us, and many are turning a blind eye.

Next 1 - 5 years should certainly provide some scientific excitement in Antarctica as the sea ice most likely continues its melting march.

Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on November 29, 2016, 02:12:14 PM
As with ice loss in the Arctic the removal of the 'damping' that the ice provides means swells can impact permafrost cliffs at the shore. In Antarctica the removal of the 'damping' means the ice shelf's come under increased forcing and so fail more often.

With places like Ross removal of the front of the shelf would lead to the rapid collapse of the rear section. Work in the mid noughties showed past 'rapid collapse' events from Ross . I was brought up to believe that East Antarctica was beyond the reach of our warming planet yet since, decade following decade, we learned that we are already seeing impacts in East Antarctica.

If IPO had flipped into its positive state ( and we are not just noting an uptick in solar reaching the Pacific now Chinese pollution is reducing?) then we should expect another 20 years or so of the kind of Sea ice melt we are currently witnessing?

Couple an IPO+ve with the ongoing repair of Ozone over the continent and we should be expecting  rapid changes around the antarctic coasts?
Title: Re: What's new in Antarctica ?
Post by: solartim27 on November 29, 2016, 04:53:09 PM
Not my discovery, but a melt pond in the Mcmurdo Sound area.
That was the shadow from a cloud.
Title: Re: What's new in Antarctica ?
Post by: magnamentis on November 29, 2016, 05:44:47 PM
Not my discovery, but a melt pond in the Mcmurdo Sound area.
That was the shadow from a cloud.

definitely blue water, what's the purpose of that post?

even if it would be gone later on, could be freeze over night hours and snow covered, not saying but i was thinking why one would see this as cloud shadow and that's just one possible explanation should the lake not be visible on a later picture while it's important to have a close look at the time an eventual image without that blue pond was taken, earlier or indeed later than the one attached.

whether it's a pond or a polnya i can't tell because i'm not 100 savvy about terms here, distinguished by size or whether the difference is that a pond could be water ON ice and a polnya just open water withing the ice :-) others know that better.
Title: Re: What's new in Antarctica ?
Post by: Tigertown on November 29, 2016, 06:12:35 PM
Not my discovery, but a melt pond in the Mcmurdo Sound area.
That was the shadow from a cloud.

I took someone else's word for it. I should have known better.
Title: Re: What's new in Antarctica ?
Post by: wehappyfew on November 29, 2016, 06:21:54 PM
Definitely shadows from clouds.

In Worldview, toggle the different satellite feeds, like Aqua/MODIS vs Terra/MODIS, and slide the opacity from 0% to 100%. The shadows move as the local time of day changes the sun angle. Observe the shadows of nearby mountains - they can be the exact same dark blue at times (but not always).

The clouds responsible are visible, but just barely (white clouds over white ice).

Observe other cloud shadows over the sloping areas of nearby ice sheets that could never support melt ponds.

I love reading Robert Scribbler, but enthusiasm can, and has, led him to jump to incorrect conclusions. We all do that, but he does it more visibly by blogging so frequently.

Title: Re: What's new in Antarctica ?
Post by: Darvince on November 29, 2016, 06:58:40 PM
There was definitely a significant amount of melt action though, as you can see the glacier turning much darker blue only between the timespan of the Aqua pass and the Terra pass, as well as it becoming much darker on the 7-2-1 bands between days.

2016-11-25: http://go.nasa.gov/2gFBCAx (http://go.nasa.gov/2gFBCAx)

2016-11-28: http://go.nasa.gov/2gFySTS (http://go.nasa.gov/2gFySTS)
Title: Re: What's new in Antarctica ?
Post by: wehappyfew on November 29, 2016, 07:14:45 PM
Thank you Darvince.
Nice choice of Base Layers to highlight the white clouds casting shadows on the light blue surface.

Worldview 11-27-16 (https://worldview.earthdata.nasa.gov/?p=antarctic&l=MODIS_Aqua_CorrectedReflectance_Bands721,MODIS_Terra_CorrectedReflectance_Bands721(hidden),VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden),Coastlines&t=2016-11-27&z=3&v=370432,-1637504,616192,-1515904)

I see five clouds. Three are casting sharp blue shadows that look like melt ponds, two at the bottom are casting grey shadows - maybe because the surface is different, or maybe the clouds are thinner.

Title: Re: What's new in Antarctica ?
Post by: Tealight on November 29, 2016, 07:23:20 PM
As solartim27 and wehappyfew said its definitely a shadow of a cloud on blue ice. However there are some smaller melt ponds scattered over the glacier.

I attached a S2A image of the region (180 degrees rotated compared to Worldview)
Title: Re: What's new in Antarctica ?
Post by: Tigertown on November 29, 2016, 07:31:21 PM
Definitely shadows from clouds.

In Worldview, toggle the different satellite feeds, like Aqua/MODIS vs Terra/MODIS, and slide the opacity from 0% to 100%. The shadows move as the local time of day changes the sun angle. Observe the shadows of nearby mountains - they can be the exact same dark blue at times (but not always).

The clouds responsible are visible, but just barely (white clouds over white ice).

Observe other cloud shadows over the sloping areas of nearby ice sheets that could never support melt ponds.

I love reading Robert Scribbler, but enthusiasm can, and has, led him to jump to incorrect conclusions. We all do that, but he does it more visibly by blogging so frequently.
Thanks. I tried that and see that it both moves and changes shape.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 04, 2016, 05:11:43 AM
The linked article is entitled: "Why is a blue cloud appearing over Antarctica?"

http://www.csmonitor.com/Science/2016/1203/Why-is-a-blue-cloud-appearing-over-Antarctica (http://www.csmonitor.com/Science/2016/1203/Why-is-a-blue-cloud-appearing-over-Antarctica)

Extract: "Noctilucent, or night-glowing, clouds appear over the South Pole each year. This year they arrived much earlier than usual, puzzling scientists.

The noctilucent clouds provide clues to the mesosphere's "connections to other parts of the atmosphere, weather, and climate," she wrote. They are summer phenomena, appearing above the Arctic in July and August and above the Antarctic in November and December."
Title: Re: What's new in Antarctica ?
Post by: magnamentis on December 04, 2016, 08:51:10 PM
would be interesting to find out how many tripple century drops have ever occurred in the antarctic or anywhere else?
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 04, 2016, 10:21:37 PM
would be interesting to find out how many tripple century drops have ever occurred in the antarctic or anywhere else?

I don't where to get the raw numbers with JAXA, but just looking at the graph, I don't see anything close to that. Off the top of my head,I think it may be a record. NSIDC I believe recently posted a drop of about 284k.
Title: Re: What's new in Antarctica ?
Post by: diablobanquisa on December 05, 2016, 12:23:55 AM
JAXA data is available here: https://ads.nipr.ac.jp/vishop/#/extent (just select "Antarctic" and click on "Download...")

In December, most years have at least one tripple century drop.
There are also a few years with quadruple century drops, and even a fivefold century drop in December 1993.


Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on December 07, 2016, 05:41:20 PM
https://www.theguardian.com/world/2016/dec/07/british-antarctic-research-station-crack-ice (https://www.theguardian.com/world/2016/dec/07/british-antarctic-research-station-crack-ice)

Looks like the B.A.S. are not taking any chances this summer?

With the ice already withdrawn in Weddell

https://worldview.earthdata.nasa.gov/?p=antarctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2016-10-02&z=3&v=-775296,1355648,-600448,1437312 (https://worldview.earthdata.nasa.gov/?p=antarctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2016-10-02&z=3&v=-775296,1355648,-600448,1437312)

will swells waggle that chasm fully across the shelf this summer? And what of the full moon in 7 days? that'll give quite a bit of a 'lift' along that central end of the chasm....
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 12, 2016, 11:04:26 PM
Under ice lakes and streams found in Antarctica similar to those in Greenland.

https://www.washingtonpost.com/news/energy-environment/wp/2016/12/12/this-dazzling-antarctic-lake-is-buried-in-floating-ice-and-that-has-scientists-worried/?utm_term=.9162c8c43b8d (https://www.washingtonpost.com/news/energy-environment/wp/2016/12/12/this-dazzling-antarctic-lake-is-buried-in-floating-ice-and-that-has-scientists-worried/?utm_term=.9162c8c43b8d)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 16, 2016, 01:49:18 AM
Subglacial basin mapped out.
www.bbc.com/news/science-environment-38333629 (http://www.bbc.com/news/science-environment-38333629)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: What's new in Antarctica ?
Post by: jai mitchell on December 16, 2016, 08:20:13 PM
https://www.washingtonpost.com/news/energy-environment/wp/2016/12/16/warm-ocean-water-is-slamming-into-and-melting-the-biggest-glacier-in-east-antarctica (https://www.washingtonpost.com/news/energy-environment/wp/2016/12/16/warm-ocean-water-is-slamming-into-and-melting-the-biggest-glacier-in-east-antarctica)

Quote
Scientists at institutions in the United States and Australia on Friday published a set of unprecedented ocean observations near the largest glacier of the largest ice sheet in the world: Totten glacier, East Antarctica. And the result was a troubling confirmation of what scientists already feared — Totten is melting from below.

see: http://advances.sciencemag.org/content/2/12/e1601610 (http://advances.sciencemag.org/content/2/12/e1601610)
Ocean heat drives rapid basal melt of the Totten Ice Shelf

    Stephen Rich Rintou et al.

Quote
Observations from the Totten calving front confirm that (0.22 ± 0.07) × 106 m3 s−1 of warm water enters the cavity through a newly discovered deep channel.

Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 20, 2016, 10:16:22 AM
The linked article discusses how right now the Australian research vessel the "Aurora Australis" is traveling to East Antarctica to gather more/new data on the stability of marine glaciers (including Totten):

http://mashable.com/2016/12/19/east-antarctica-totten-glacier-melt-climate/#hmoYBXlpksqo (http://mashable.com/2016/12/19/east-antarctica-totten-glacier-melt-climate/#hmoYBXlpksqo)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on December 20, 2016, 06:13:13 PM
I saw this little video clip, and couldn't help but wonder about all the yellowish gunk on the bottom of the ice.  Anyone have any thoughts?
Quote
The bow of the NG/Linblad Explorer slides through the seasonal sea ice on the Antarctic Peninsula.
https://www.instagram.com/p/BOOVgZujbuL/ (https://www.instagram.com/p/BOOVgZujbuL/)
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 20, 2016, 07:13:13 PM
Phytoplankton. Recently discovered under Arctic ice, now looks to be under Antarctic ice also. The water is relatively warm just below the surface.
Title: Re: What's new in Antarctica ?
Post by: georged on December 21, 2016, 04:04:40 AM
Antarctic under-ice phytoplankton has been well known for a while. It was a fairly established subject when my housemate was doing her PhD on it in 2006.
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 21, 2016, 06:19:31 AM
Just looking into news of the warmer than usual circumpolar current that is melting away at the Totten Ice Shelf and possibly making a cavity  at the entrance of an under-water canyon about 1200 meters or less down. This is a big concern because of a retrograde inland that would channel the warm water under the glacier. The basin there contains a huge volume of ice. I am learning as I go on this, so maybe others can add details. I do have some temp and salinity charts for the area of concern.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: What's new in Antarctica ?
Post by: sidd on December 21, 2016, 06:44:42 AM
Ice at depth melts easier, i seem to recall that at 1000m ice melts at -1.2C, which is around 2.5C colder than water temp at that depth from the chart above.
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 21, 2016, 06:53:52 AM
Ice at depth melts easier, i seem to recall that at 1000m ice melts at -1.2C, which is around 2.5C colder than water temp at that depth from the chart above.
Allowing another  -1.8 for salinity would make that about a 4.3oC differential.
Title: Re: What's new in Antarctica ?
Post by: sidd on December 21, 2016, 10:48:56 PM
The salinity effect is irrelevant, since the phenoenon under discussion is the met of glacial ice derived from fresh water. If we were speaking of melting saline ice or freezing saline water the argument might hold. But we are speaking of melt of fresh ice.
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 22, 2016, 01:02:16 AM
The area under attack from the warm water has a current flowing against it. So it is a steady flow of salt water, not stationary,so it doesn't cool like saltwater melting ice normally would. Wouldn't this make the salt more effective than normal?
Title: Re: What's new in Antarctica ?
Post by: georged on December 22, 2016, 02:13:10 AM
Just looking into news of the warmer than usual circumpolar current that is melting away at the Totten Ice Shelf and possibly making a cavity  at the entrance of an under-water canyon about 1200 meters or less down. This is a big concern because of a retrograde inland that would channel the warm water under the glacier. The basin there contains a huge volume of ice. I am learning as I go on this, so maybe others can add details. I do have some temp and salinity charts for the area of concern.

It's my understanding that this depression is due to glacial weight? In any case, it is over 2700m deep at the grounding line. This is a phenomenal deep surface.

http://imagecache.jpl.nasa.gov/images/640x350/earth20150316b-16-640x350.jpg (http://imagecache.jpl.nasa.gov/images/640x350/earth20150316b-16-640x350.jpg)
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 22, 2016, 02:20:06 AM
Thanks georged. Hope you don't mind if I go ahead and post that image, as it is very helpful in understanding the situation better.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: What's new in Antarctica ?
Post by: sidd on December 22, 2016, 05:40:34 AM
Re: saltwater current more effective than fresh at melting fresh ice

call the current velocity v, current density rho, specific heat Cp, the area exposed to the current A, and the temperature drop of the current dT     

in order of magnitude terms the heat extracted from the current Q available for ice melt  is

Q=rho*Cp*A*v*dT
 
(This neglects melt efflux mixed into the impinging current, roughness, turbulence and a whole bunch of things. But to order of magnitude, is ok)

Both rho and Cp are functions of salinity (and pressure and temperature ...) From the difference in the term rho*Cp between fresh water and water and sea water (at the relevant pressure and temperature ...)  we can calculate the difference in heat delivered. I leave this as an excercise for the reader, but i think it is a few percent.

sidd
Title: Re: What's new in Antarctica ?
Post by: Tigertown on December 22, 2016, 06:11:13 AM
Thanks sidd. From what I understand it is a very strong current right now. Looking forward to any additional info that anyone comes across about this in the near future.
Title: Re: What's new in Antarctica ?
Post by: johnm33 on December 22, 2016, 01:43:44 PM
Thanks for that image g+Tt, I'm going to keep an eye on hy-com for an outburst of fresh water thereabouts.
Title: Re: What's new in Antarctica ?
Post by: charles_oil on December 26, 2016, 11:30:25 AM
Huffington article and video about seafloor life in Antarctica - and the possible effects of CO2 changes.

http://www.huffingtonpost.co.uk/entry/rare-video-of-the-antarctic-seafloor-reveals-stunning-landscape_uk_585ab317e4b0d590e44ca05c?icid=maing-grid7%7Cmain5%7Cdl1%7Csec3_lnk1%26pLid%3D1285279572_uk (http://www.huffingtonpost.co.uk/entry/rare-video-of-the-antarctic-seafloor-reveals-stunning-landscape_uk_585ab317e4b0d590e44ca05c?icid=maing-grid7%7Cmain5%7Cdl1%7Csec3_lnk1%26pLid%3D1285279572_uk)

When you think of the seafloor in Antarctica you would be forgiven for thinking that it’s probably a barren wasteland, covered by vast swathes of ice in freezing cold temperatures.

While those last two points are accurate, an Australian Antarctic Division underwater research robot has captured a rare glimpse into the astonishing diversity that actually exists in this remotest of landscapes.

Rather than being a lifeless all-consuming mass of grey it seems Antarctica’s seafloor is brimming not only with life, but some dazzling colours too.
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on December 30, 2016, 12:09:56 AM
The linked article is entitled: "Satellite spots massive object hidden under the frozen wastes of Antarctica", and indicates that there may be a large asteroid impact crater buried beneath the ice in Wilkes Land.

http://www.news.com.au/technology/science/satellite-spots-massive-object-hidden-under-the-frozen-wastes-of-antarctica/news-story/dfdc58ee88bde178ceb611782185f39a (http://www.news.com.au/technology/science/satellite-spots-massive-object-hidden-under-the-frozen-wastes-of-antarctica/news-story/dfdc58ee88bde178ceb611782185f39a)

Extract: "The Sun reports the huge and mysterious “anomaly” is thought to be lurking beneath the frozen wastes of an area called Wilkes Land.

It stretches for a distance of 151 miles across and has a maximum depth of about 848 metres.
Some researchers believe it is the remains of a truly massive asteroid which was more than twice the size of the Chicxulub space rock which wiped out the dinosaurs.

If this explanation is true, it could mean this killer asteroid caused the Permian — Triassic extinction event which killed 96 per cent of Earth’s sea creatures and up to 70 per cent of the vertebrate organisms living on land."
Title: Re: What's new in Antarctica ?
Post by: Tealight on January 14, 2017, 08:02:26 PM
Iceberg B31 (calved in November 2013, from Pine Island Glacier) was mostly visible for a few days. It appears to stay in the same position, but it spins at around 50 degrees per day or a full rotation in 7 days. The edges are around 10km from the rotation center so they move at 9km/day linear speed. Does this greatly increase the melt rate?

http://go.nasa.gov/2iseuFX (http://go.nasa.gov/2iseuFX)
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 14, 2017, 09:39:39 PM
I saw two nice bits on research stations in Antarctica with lots of nice pictures.

How Antarctic bases went from wooden huts to sci-fi chic:
http://www.bbc.co.uk/news/magazine-38574003 (http://www.bbc.co.uk/news/magazine-38574003)

The incredible 'mad max' journey across Antarctica: Stunning satellite image reveals gruelling trek to resupply Earth's most remote research station
 Gruelling 10 day traverse is to reach Concordia, a giant two towered research station in Antarctica
The 'caravans' carry up to 300 tonnes of fuel, food and heavy equipment in 300 m-long convoys
http://www.dailymail.co.uk/sciencetech/article-4114796/The-incredible-mad-max-journey-Antarctica-Stunning-satellite-image-reveals-gruelling-trek-resupply-Earth-s-remote-research-stations.html (http://www.dailymail.co.uk/sciencetech/article-4114796/The-incredible-mad-max-journey-Antarctica-Stunning-satellite-image-reveals-gruelling-trek-resupply-Earth-s-remote-research-stations.html)
Title: Re: What's new in Antarctica ?
Post by: iwantatr8 on January 20, 2017, 01:46:15 PM
This looks like it might be a very useful resource for monitoring antartica data.

http://quantarctica.npolar.no/ (http://quantarctica.npolar.no/)

but it's a bit big!

Title: Re: What's new in Antarctica ?
Post by: Laurent on February 13, 2017, 08:32:10 PM
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2888.html (http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2888.html)
Enhanced weathering and CO2 drawdown caused by latest Eocene strengthening of the Atlantic meridional overturning circulation

Abstract

On timescales significantly greater than 105 years, atmospheric pCO2 is controlled by the rate of mantle outgassing relative to the set-point of the silicate weathering feedback. The weathering set-point has been shown to depend on the distribution and characteristics of rocks exposed at the Earth’s surface, vegetation types and topography. Here we argue that large-scale climate impacts caused by changes in ocean circulation can also modify the weathering set-point and show evidence suggesting that this played a role in the establishment of the Antarctic ice sheet at the Eocene–Oligocene boundary. In our simulations, tectonic deepening of the Drake Passage causes freshening and stratification of the Southern Ocean, strengthening the Atlantic meridional overturning circulation and consequently raising temperatures and intensifying rainfall over land. These simulated changes are consistent with late Eocene tectonic reconstructions that show Drake Passage deepening, and with sediment records that reveal Southern Ocean stratification, the emergence of North Atlantic Deep Water, and a hemispherically asymmetric temperature change. These factors would have driven intensified silicate weathering and can thereby explain the drawdown of carbon dioxide that has been linked with Antarctic ice sheet growth. We suggest that this mechanism illustrates another way in which ocean–atmosphere climate dynamics can introduce nonlinear threshold behaviour through interaction with the geologic carbon cycle.

Title: Re: What's new in Antarctica ?
Post by: solartim27 on February 13, 2017, 10:57:21 PM
Just a fun gif of an iceberg wreacking havoc.  I believe it is B15AA.
Title: Re: What's new in Antarctica ?
Post by: zxy on February 26, 2017, 05:05:42 AM
Enderby Land has a chunk of ice approx 50km x 150km floating away. In gif is an animation from 10.2 to 25.2 2017.

And the link to worldview site:

https://worldview.earthdata.nasa.gov/?p=antarctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2017-02-25&z=3&v=545791.9999999998,1195776,2184192,1994496&ab=off&as=2017-02-10&ae=2017-02-25&av=1.5&al=false (https://worldview.earthdata.nasa.gov/?p=antarctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2017-02-25&z=3&v=545791.9999999998,1195776,2184192,1994496&ab=off&as=2017-02-10&ae=2017-02-25&av=1.5&al=false)

Title: Re: What's new in Antarctica ?
Post by: bairgon on February 26, 2017, 07:35:07 AM
Enderby Land has a chunk of ice approx 50km x 150km floating away. In gif is an animation from 10.2 to 25.2 2017.

That area suffered significant melting in April 2016, so the ice there is only one year old:

Title: Re: What's new in Antarctica ?
Post by: solartim27 on February 26, 2017, 07:25:33 PM
Just saw this 2015 documentary on Claude Lorius, "Antarctica  Ice and Sky"  Lots of great historical video and  information on doing the initial research.

http://imdb.com/rg/an_share/title/title/tt4466550/ (http://imdb.com/rg/an_share/title/title/tt4466550/)
Title: Re: What's new in Antarctica ?
Post by: dingojoe on February 26, 2017, 10:03:39 PM
Enderby Land has a chunk of ice approx 50km x 150km floating away. In gif is an animation from 10.2 to 25.2 2017.

That area suffered significant melting in April 2016, so the ice there is only one year old:

We've talked about that area on various threads, but it would have never occurred to me to look at April time frame for fast ice breakdown.
Title: Re: What's new in Antarctica ?
Post by: bairgon on February 27, 2017, 05:44:31 PM
Looking at the Weddell Sea, I've noticed that the ice has consistently been moving north from the shore for the last month or so. Hope the gif works; otherwise click.

New ice is forming in the gap. Also interesting to see the grounded iceberg which is perhaps helping to anchor the sea ice, but to little effect in this sequence.

Link: https://worldview.earthdata.nasa.gov/?p=antarctic&l=MODIS_Terra_CorrectedReflectance_TrueColor,MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),Coastlines&t=2017-02-27&z=3&v=-1769401.1403176677,742212.6312051003,-786361.1403176677,1246532.6312051003&ab=off (https://worldview.earthdata.nasa.gov/?p=antarctic&l=MODIS_Terra_CorrectedReflectance_TrueColor,MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),Coastlines&t=2017-02-27&z=3&v=-1769401.1403176677,742212.6312051003,-786361.1403176677,1246532.6312051003&ab=off)
Title: Re: What's new in Antarctica ?
Post by: Red on February 27, 2017, 09:34:17 PM
Enderby Land has a chunk of ice approx 50km x 150km floating away. In gif is an animation from 10.2 to 25.2 2017.

That area suffered significant melting in April 2016, so the ice there is only one year old:

We've talked about that area on various threads, but it would have never occurred to me to look at April time frame for fast ice breakdown.
If you go back through the Aprils to '13 you'll see that '16 was the first year that most of the bay opens. So a lot of that was MYI that let go last year. This melt season if you look at Ludzow-Holm Bay, the left side started to open against the mainland back in early December. This was melt out in MYI ice that existed at least back to '13, (thats as far as I know how to get to). Comparing various areas of East Antarctica's satellite records for the years from '13 to '16 it appears that every year there is a little more MYI goes missing by April. The area just in front of the Shirase toe has taken quite a hit this year compared to last. There are some icebergs coming free that haven't been loose in years. A little more MYI being lost consistently every year for the past four is not the end of days but, it would seem to indicate an increase in energy arriving at the surface during melt season year over year.
Title: Re: What's new in Antarctica ?
Post by: Neven on March 27, 2017, 09:00:59 PM
Here's a comment Hyperion made in the wrong thread:

Thanks slow wing. Especially for pointing out my elderly muddleheaded mixuped mismemoring of the enthalpy of vapourisation figure. How embarrassing to under calculate a figure by some 500 times. ::)
 And you Jai. Wish I had more time right now to read those papers. Very busy day unfortunately.  These worldwide changes to the circulation patterns we are used to seem to be happening almost hour by hour right now. It does seem like, particularly in the polar regions the tropopause has lifted suddenly and dramatically as predicted by some models and proposed as necessary for single cell circulation regimes in past equable climates. As for whether I'm a magnitude out in those estimated flow rates? As an engineer you tend to go "how bad could it get? What is the level of safety we need built in to handle it?" the precautionary principle with a mind to the future is the mindset. Not scientific understatement, with no credibility placed on any data but the solidly studied and proven historic data. And so I think it is possibly the best introduction we currently have, to what to expect in the late Arctic summer to observe whats going on down south here right now. That TPW fist that was heading for the Antarctic peninsula is now there. 15kg/sqm of water aboard and suddenly the whole peninsula is hotter by 6-10 degC. Up to 6 above freezing in places. The one heading for Ross, south of NZ is packing 30kg/sqm and came from mainly over Australia.  The Fist from the Indian Ocean Tropics is packing 45kg/sqm and just about to pass the Kerguellens at 52 sth and ram East Antarctica.
The huge 930hpa low taking up the whole space between Australia and Antarctica is the scariest mother I've ever seen, and looks capable of grabbing the whole of the Pacific Tropical airmass and squeezing all of it out on Antarctica. Especially as it comes across and meshes with the Anticyclone taking up nearly all the cental south pacific. Also absurdly large.
No I don't think its usual for the whole of the south Pacific trades to be turned from the tropics and sprayed on Antarctica Tigertown. It happened two weeks ago. There's even some of the Trades from Nth of the equator being pulled into the flow that just hit the Antarctic Peninsula, and the big puddle that just grazed our New Zealand east coast that's setting itself up to be shot south from between those two Flywheels.
Your Nth Atlantic Storm is looking serious. Its very tall, above 30km. Reckon its going to do much the same with the atlantic Tropical Air. We seem to have transitioned to a primarily Ferral cell circulation mode. The angular momentum of Polewards air is being stored in the jets, and retrieved by the high altitude equator wise backflows IMHO.


https://earth.nullschool.net/#current/wind/isobaric/1000hPa/overlay=total_precipitable_water/azimuthal_equidistant=159.15,-58.94,371
Title: Re: What's new in Antarctica ?
Post by: DrTskoul on March 30, 2017, 12:21:04 AM
Scientists highlight Antarctic ice upheaval in response to prehistoric climate change (https://m.phys.org/news/2017-03-scientists-highlight-antarctic-ice-upheaval.html)

Quote
The research, led by palaeoclimatologist Dr Diederik Liebrand as part of an International Ocean Discovery Program collaboration, suggests that 20 to 30 million years ago the Antarctic periodically gained and lost huge ice caps – equivalent to the entire modern-day East Antarctic Ice Sheet.

Dr Liebrand said: "Our research shows that even slow, naturally forced climate change is capable of driving rapid large-scale changes in ice volume in Antarctica – and therefore global sea levels.

"This is of particular interest to scientists because humans are now the main agents of climate change, and the rates of change today are much faster than those that occurred millions of years ago during the interval that we studied.

"Increasingly we are understanding that the Antarctic ice cap is not some enduring monolithic block but a much more slippery ephemeral beast – and the implications of that realisation for the future of Antarctic ice sheets in a very rapidly warming world have not escaped us."

The scientists examined oxygen isotopes in fossilised micro-organisms – found in a drill core of marine sediments taken from a water depth of 2.5km in the South Atlantic – to reach their findings, published this week in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Evolution of the early Antarctic ice ages, PNAS,
www.pnas.org/cgi/doi/10.1073/pnas.1615440114 (http://www.pnas.org/cgi/doi/10.1073/pnas.1615440114)

Provided by: University of Southampton
Title: Re: What's new in Antarctica ?
Post by: wili on April 03, 2017, 02:46:36 AM
This isn't new (sorry if it's already been posted here), and it's not exclusively relevant to the Antarctic, but it's a nice concise summary of the major feedbacks that affect ice sheet melt.

http://www.bitsofscience.org/sea-level-rise-ice-sheet-dynamics-melting-feedbacks-acceleration-7295/#more-7295 (http://www.bitsofscience.org/sea-level-rise-ice-sheet-dynamics-melting-feedbacks-acceleration-7295/#more-7295)

(Thanks to chilyb at PeakOilForums for the link)
Title: Re: What's new in Antarctica ?
Post by: FredBear on April 03, 2017, 01:14:41 PM
On arctic io :-  Some ice in old Larsen B area broke away 18/03/2017, lot more looks as if it may have melt-water from 29th? Bit late in the season but might be katabatic winds, other ice breaking off and blowing east further south (sea ice n. end of Larsen C, 28/03?)  .   .   .   
Title: Re: What's new in Antarctica ?
Post by: sidd on April 07, 2017, 07:53:31 AM
China will make hole on Amery:

http://en.people.cn/n3/2017/0406/c90000-9199657.html (http://en.people.cn/n3/2017/0406/c90000-9199657.html)

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on April 11, 2017, 11:17:07 PM
Landsat-8 derived surface velocities for 2014 and 2015 with a detailed comparison to previous estimates at doi:10.5194/tc-2017-34

Many pretty pictures. Worries in the Wilkes Basin. Open access. Read all about it at

 http://www.the-cryosphere-discuss.net/tc-2017-34/ (http://www.the-cryosphere-discuss.net/tc-2017-34/)
Title: Re: What's new in Antarctica ?
Post by: Hyperion on April 12, 2017, 10:29:41 AM
Quote
Cycles 57 and 49 (at ∼22.7 and 19.5 My ago), which are characterized by distinctly sawtooth-shaped ∼110-ky cycles, suggesting a causal link between cycle amplitude and asymmetry during the Early Miocene, but not during the MOGI. The distinctly asymmetric cycles suggest that the Early Miocene Antarctic ice sheets periodically underwent intervals of growth that were prolonged relative to astronomical forcing and then underwent subsequent rapid retreat in a manner akin to the glacial terminations of the Late Pleistocene glaciations, in which the large ice sheets of the Northern Hemisphere were major participants (27, 28, 32). The highly asymmetric (sawtooth) nature of Late Pleistocene glacial−interglacial cycles is thought to originate from a positive ice mass balance that persists through several precession- and obliquity-paced summer insolation maxima. This results in decreasing ice sheet stability and more rapid terminations every ∼110 ky, once the ablation of the Northern Hemisphere ice sheets increases dramatically in response to the next insolation maximum. The increase in ablation is caused by lowered surface elevation of the ice sheets resulting from crustal sinking and delayed isostatic rebound (33). Similar mechanisms are implied for the large Antarctic ice sheets of the OMT (∼22.5 My ago) but it is less clear why the smaller ice sheets of the Early Miocene (∼19.5 My ago) would exhibit this distinctly sawtooth-shaped pattern of growth and decay (Fig. 3).

As they point out here "delayed isostatic rebound" can be a factor in rapid ice sheet collapses. Though this is stated as causing rapid retreats through ablation, bottom melt processes could be a larger factor. Especially with Below sea level interiors like WA and Greenland. There is possibility here that this study, and even our data of the holocene deglaciation has even more rapid advance/ retreat behaviour smoothed out in published studies by preconceptions that have their root in the scientific consensus held until recently that major changes in large ice sheets take thousands of years to occur. Obviously data collected loses resolution with antiquity, and its not uncommon unfortunately for "anomalous" samples that don't fit the paradigm to be discarded and not even be mentioned in publication. As we appear to be learning that Atmosphere and ocean heat transport changes can produce large and rapid consequence, perhaps we should be considering the possibility that there may have been big Antarctic and Greenland melt backs in the meltwater pulses coming out of the last Glaciation. A process where the Laurentide and European Ice sheet melts trigger increased heat transport to poles via big storm systems caused by the temperature differentials in SSTs, then the process see-saws, causing a rapid meltback at the poles along with partial rebuilding of the L and E sheets via increased snowfalls caused by polar cyclone factories seems feasible. This would dampen the sea level changes as the 6x current total terrestrial ice sheet mass of 20ka bp crashed in several pulses over 10000 years to near current levels. Not a situation we currently can look forward to. With too much heat in the system the Temperate latitude caps can't build as the polar ones crash. But the runaway escalation of cyclone heat transport as Hansen's paper proposed for the end of the last interglacial 120 ka bp sure can. With the extra issues of far higher greenhouse burden and orbital forcings being more favourable to rapid meltings now.
Title: Re: What's new in Antarctica ?
Post by: sidd on April 20, 2017, 12:12:32 AM
New paper about surface meltwater in Antarctica doi:10.1038/nature22049
I attach Fig 1
Title: Re: What's new in Antarctica ?
Post by: sidd on April 20, 2017, 12:14:13 AM
And a paper showing evidence for meltwater stabilization of an ice shelf (?!) doi:10.1038/nature22048
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on April 20, 2017, 12:33:23 AM
New paper about surface meltwater in Antarctica doi:10.1038/nature22049

The associated article is entitled: "Scientists have discovered vast systems of flowing water in Antarctica. And that worries them."

https://www.washingtonpost.com/news/energy-environment/wp/2017/04/19/the-surface-of-antarctica-is-covered-with-flowing-water-that-has-scientists-worried/?utm_term=.a447caa06cea (https://www.washingtonpost.com/news/energy-environment/wp/2017/04/19/the-surface-of-antarctica-is-covered-with-flowing-water-that-has-scientists-worried/?utm_term=.a447caa06cea)

Extract: "The surface of the remote Antarctic ice sheet may be a far more dynamic place than scientists imagined, new research suggests. Decades of satellite imagery and aerial photography have revealed an extensive network of lakes and rivers transporting liquid meltwater across the continent’s ice shelves — nearly 700 systems of connected pools and streams in total.

“A handful of previous studies have documented surface lakes and streams on individual ice shelves over a span of a few years,” glaciologist Alison Banwell of the University of Cambridge wrote in a comment on the new research, published Wednesday in the journal Nature. “But the authors’ work is the first to extensively map meltwater features and drainage systems on all of Antarctica’s ice shelves, over multiple decades.”

The findings, presented Wednesday in a pair of papers in Nature, could upend our understanding of the way meltwater interacts with the frozen ice sheet."

Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on April 24, 2017, 01:47:16 AM
And a paper showing evidence for meltwater stabilization of an ice shelf (?!) doi:10.1038/nature22048

Here is a more complete reference & a linked to an open access cop of the paper:

Jonathan Kingslake, Jeremy C. Ely, Indrani Das & Robin E. Bell (20 APRIL 2017), "Widespread movement of meltwater onto and across Antarctic ice shelves", NATURE, VOL 544, 349; doi:10.1038/nature22049

https://www.nature.com/articles/nature22049.epdf?referrer_access_token=F81z0TqwjGmb71By493OxNRgN0jAjWel9jnR3ZoTv0NWLAFAcjzSECmaCP-TuhnQnGZAtnvyAOn7AnGvU4eFIhvSEXoC1C_eSvhX66G7wIrelRihqRI2ZJiLFK7noXL2wRaVkuwepFW4IPEnI18R27P44CGAGzLWoi2s9p-L4iIXUTf9xLPsUKVG5QyR-syQVj_dX8IR8ikWvtV8j6UV4zYWWaEHHTVDErJ8Je1mG9hoI8AgdRFZYtm_R8vq6R96&tracking_referrer=www.cbsnews.com (https://www.nature.com/articles/nature22049.epdf?referrer_access_token=F81z0TqwjGmb71By493OxNRgN0jAjWel9jnR3ZoTv0NWLAFAcjzSECmaCP-TuhnQnGZAtnvyAOn7AnGvU4eFIhvSEXoC1C_eSvhX66G7wIrelRihqRI2ZJiLFK7noXL2wRaVkuwepFW4IPEnI18R27P44CGAGzLWoi2s9p-L4iIXUTf9xLPsUKVG5QyR-syQVj_dX8IR8ikWvtV8j6UV4zYWWaEHHTVDErJ8Je1mG9hoI8AgdRFZYtm_R8vq6R96&tracking_referrer=www.cbsnews.com)
Title: Re: What's new in Antarctica ?
Post by: sidd on April 25, 2017, 02:26:02 AM
"And a paper showing evidence for meltwater stabilization of an ice shelf (?!) doi:10.1038/nature22048"

the link above in the quote is to the Bell paper, not the Kingslake paper.

That Bell paper is quite interesting. Hydrofracture instability is slowed greatly by efficient export of surface melt.

"The ­calculated water export ranges from 0.04 km^3 to 0.56 km^3 in each season. In just seven days, the waterfall can export the entire annual surface melt volume produced by a melt rate of 0.5 m/yr over the shear-margin catchment. Present ice-sheet models produce rapid disintegration when surface melt rates reach 1.5 m/yr. However, our results show that this amount of ­surface melt could be removed by the waterfall in 21 days (Extended Data Fig. 6). This efficient export of surface meltwater highlights the capacity of rivers to efficiently buffer ice shelves against the damaging storage of melt."

Well, that immediately raises the question, why did this not buffer Larsen before it fell apart ? I wonder if Larsen has rivers for years before it fell apart, by we were not watching it carefully enuf. Well, good news, for a change, if it is borne out.

sidd

Title: Re: What's new in Antarctica ?
Post by: sidd on April 25, 2017, 02:30:18 AM
Re: Kingslake paper, doi:10.1038/nature22049

In the figure 1 i included earlier, inset d) is the the Roy Bauduoin shelf. There is a new paper at cryosphere-discuss by Berger et al. doi:10.5194/tc-2017-41 about spatial variation in basal melting on this shelf.

http://www.the-cryosphere-discuss.net/tc-2017-41/ (http://www.the-cryosphere-discuss.net/tc-2017-41/)

sidd
Title: Re: What's new in Antarctica ?
Post by: crandles on April 30, 2017, 05:20:21 PM
Antarctica's troublesome 'hairdryer winds' (ie 'Foen' winds)
http://www.bbc.co.uk/news/science-environment-39759329 (http://www.bbc.co.uk/news/science-environment-39759329)

Quote
A new study has found an atmospheric melting phenomenon in the region to be far more prevalent than anyone had realised.
Title: Re: What's new in Antarctica ?
Post by: Juan C. García on May 06, 2017, 04:00:50 AM
UAE plans to drag an ICEBERG from Antarctica to provide drinking water for millions

http://www.dailymail.co.uk/sciencetech/article-4476272/UAE-plans-drag-ICEBERG-Antarctic.html (http://www.dailymail.co.uk/sciencetech/article-4476272/UAE-plans-drag-ICEBERG-Antarctic.html)

 :o :P
Title: Re: What's new in Antarctica ?
Post by: FredBear on May 06, 2017, 12:50:09 PM
The iceberg would set an interesting set of environmental questions :-
!. Presumeably it would become surrounded with a pool of very cold fresh water to upset the local aquatic life.
2.The cold would strip moisture from the atmosphere, making it even drier, fog might even form?
3. Would the iceberg remain stable during the "mining", or would it topple or even explode?
4. Where do you park it?
5. ??

( I did once use a 2 litre, -20oC ice block as emergency cooling for a marine aquarium with good circulation - it cracked quite loudly and melted fast!)
Title: Re: What's new in Antarctica ?
Post by: Juan C. García on May 06, 2017, 04:11:31 PM
The iceberg would set an interesting set of environmental questions :-
!. Presumeably it would become surrounded with a pool of very cold fresh water to upset the local aquatic life.
2.The cold would strip moisture from the atmosphere, making it even drier, fog might even form?
3. Would the iceberg remain stable during the "mining", or would it topple or even explode?
4. Where do you park it?
5. ??

( I did once use a 2 litre, -20oC ice block as emergency cooling for a marine aquarium with good circulation - it cracked quite loudly and melted fast!)

Suppose that it could work. Do we need to take out ice from Antarctica to make greener the African deserts? To make them cooler on a world in which humanity is still emitting greenhouse gases?

They are talking about having infrastructure to make a routine with this icebergs movement!

Hope it will not work, if they try it!
Title: Re: What's new in Antarctica ?
Post by: ghoti on May 06, 2017, 04:46:24 PM
Towing icebergs for fresh water is a zombie idea that comes up regularly and never pans out. Here's an article from 2011 about it...
https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/]
[url]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/ (http://[url)[/url]
Title: Re: What's new in Antarctica ?
Post by: Juan C. García on May 09, 2017, 11:07:40 PM
Towing icebergs for fresh water is a zombie idea that comes up regularly and never pans out. Here's an article from 2011 about it...

[url]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/]
[url]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/ (http://[url=https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/)[/url]

Thanks for the answers, Ghoti and FredBear!  ;)
Title: Re: What's new in Antarctica ?
Post by: sidd on May 11, 2017, 06:52:20 PM
Hellmer et al: Filchner-Ronne in jeopardy, as Hellmer had previously pointed out, he now puts timeframe on the cold-cavity to warm cavity transition.

"Derivatives of Circumpolar Deep Water are directed southward underneath the Filchner–Ronne Ice Shelf, warming the cavity and dramatically increasing basal melting ... The process is irreversible with a recurrence to twentieth-century atmospheric forcing and can only be halted through prescribing a return to twentieth-century basal melt rates. This finding might have strong implications for the stability of the Antarctic ice sheet."

"Our experiments indicate that the link between the hydrography on the southern Weddell Sea continental shelf and melt rates beneath the Filchner–Ronne Ice Shelf is controlled by a positive feedback mechanism: Once the reversal of the near-bottom density gradient across the Filchner Trough, together with a rising coastal thermocline, facilitates the direct inflow of the slope current into the trough, warm deep water flushes the ice shelf cavity, causing its warming, enhanced basal mass loss, and a vigorous outflow of glacial meltwater. The latter further freshens the shelf water and thus maintains a density and flow structure at the sill that supports further access of warm water to the ice shelf cavity. The increase in basal melting accelerates the cavity circulation, drawing in even more warm water of open ocean origin—a self-intensifying mechanism. Although the initial trigger for this transition is freshening on the continental shelf as a result of atmosphere–ocean interactions, once the system is in the warm-shelf phase, the only way to stop the inflow of the warm water is to return to twentieth-century atmospheric conditions and to reduce the meltwater input. At first, the latter could be realized by a reduction in the floating portion of the ice sheet. However, the resulting loss of buttressing of the inland ice sheet would accelerate the draining ice streams. The discharge of ice from the relevant catchment basin and a significant contribution to global sea level will be inevitable."

doi: 10.1175/JCLI-D-16-0420.1

open access. Read all about it.

sidd

Title: Re: What's new in Antarctica ?
Post by: sidd on May 11, 2017, 07:18:59 PM
An addendum to my previous comment:

Amundsen Sea glaciers are already destabilized. Filchner Ronne to go around 2070. Wonder how soon until the Ross goes, unleasing threeway attack on WAIS, and eventual open water communication as there once was. That recalled bryozoan data,  cf Vaughn(2011) doi:10.1029/2011GC003688 , also open access, read all about it. That paper says, hopefully,

"Continued ice-loss at present rates would open seaways between Amundsen and Weddell seas (A-W), and Amundsen and Bellingshausen seas (A-B), in around one thousand years. "

I think the timescale might be an order of magnitude faster. Ominously:

" ...  we conclude that opening could have occurred in MIS 5e (100 ka BP) when Antarctica was warmer than present and likely contributed to global sea levels higher than today."

Thats the Eemian. We are in Eemian temperatures now.

sidd
Title: Re: What's new in Antarctica ?
Post by: TerryM on May 14, 2017, 02:43:39 PM
Towing icebergs for fresh water is a zombie idea that comes up regularly and never pans out. Here's an article from 2011 about it...

[url]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/]
[url]https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/ (http://[url=https://www.theatlantic.com/technology/archive/2011/08/the-many-failures-and-few-successes-of-zany-iceberg-towing-schemes/243364/)[/url]


Had a prof in the early 60's that had worked on Habakkuk and was still an enthusiast. Insisted that with chiller equipment aboard all that would be necessary after a bombing would be a fire hose to fill any craters. He was teaching in Hamilton at that time but did have a British accent.


I'd read something a decade or so ago where iceberg cowboys off Newfoundland were grounding them in coves and selling the melt water to a brewery because of it's purity.
Wonder it Cate would know?


Slightly OT, but I believe they mined the Mendenhall Glacier in Alaska for cooling cocktails in San Francisco from the Klondike days.
Terry
Title: Re: What's new in Antarctica ?
Post by: wili on May 17, 2017, 04:07:10 AM
Not sure if this has already been posted somewhere--Al Jazeera has a story on Antarctica:

http://interactive.aljazeera.com/aje/2017/antarctica-voyage/index.html#11 (http://interactive.aljazeera.com/aje/2017/antarctica-voyage/index.html#11)

Title: Re: What's new in Antarctica ?
Post by: wili on May 18, 2017, 05:20:44 PM
And now NYT has started a series on Antarctica as well...I think that's what's called 'trending'!

https://www.nytimes.com/interactive/2017/05/18/climate/antarctica-ice-melt-climate-change.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=second-column-region&region=top-news&WT.nav=top-news&_r=0 (https://www.nytimes.com/interactive/2017/05/18/climate/antarctica-ice-melt-climate-change.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=second-column-region&region=top-news&WT.nav=top-news&_r=0)
Title: Re: What's new in Antarctica ?
Post by: wili on May 18, 2017, 11:25:59 PM
And now there's a story in the Guardian, for the trifecta!

https://www.theguardian.com/science/2017/may/18/climate-change-is-turning-antarctica-green-say-reseatchers (https://www.theguardian.com/science/2017/may/18/climate-change-is-turning-antarctica-green-say-reseatchers)

 Climate change is turning Antarctica green, say researchers

Quote
In the past 50 years the quantity and rate of plant growth has shot up, says study, suggesting further warming could lead to rapid ecosystem changes
Title: Re: What's new in Antarctica ?
Post by: gerontocrat on May 20, 2017, 04:41:10 PM
Couldn't resist this image of the jetstream over Antarctica. An almost perfect outer ring with enormous (Rossby?) waves inside.

Title: Re: What's new in Antarctica ?
Post by: charles_oil on May 21, 2017, 10:05:07 AM

And CNN has picked up on greening too (quiet day in Trumpton for once)


http://edition.cnn.com/2017/05/19/europe/climate-change-antarctica-moss/index.html (http://edition.cnn.com/2017/05/19/europe/climate-change-antarctica-moss/index.html)

Title: Re: What's new in Antarctica ?
Post by: Hyperion on May 26, 2017, 02:25:07 PM
GADZOOKS!

 :o
Title: Re: What's new in Antarctica ?
Post by: Hyperion on June 10, 2017, 03:33:40 PM
Folks. We have a new record 1062 Hecto-pascal's in Antarctica. And in close proximity we have two deep depressions with 942 hecto-pascal centres. Thats a 100 hpa dipole differential. About 1.4 pounds per square inch. The Antarctic polar cell is revving. And Ferrell's are grunting strongly too mr Hadley is looking tame. https://earth.nullschool.net/#2017/06/10/0900Z/wind/isobaric/250hPa/overlay=mean_sea_level_pressure/winkel3=-189.41,-84.08,600/loc=93.006,-83.917
Title: Re: What's new in Antarctica ?
Post by: bairgon on June 23, 2017, 02:09:12 PM
Article on the UK Guardian newspaper website today about the changes in Antarctica and whether they are due to climate change. https://www.theguardian.com/science/2017/jun/23/melting-and-cracking-is-antarctica-falling-apart-climate-change (https://www.theguardian.com/science/2017/jun/23/melting-and-cracking-is-antarctica-falling-apart-climate-change)

Quote
Melting and cracking – is Antarctica falling apart?

Quote
The answer to these questions is no. Glaciologists are not alarmed about most of these processes; they are examples of Antarctica simply doing what we know Antarctica has done for thousands of years. But because there is a potential link between the ice sheet and climate change, glaciologists are suddenly faced with a situation where the spotlight is on our science on a seemingly daily basis, and every time a crack grows, or a meltstream forms, it becomes news. The situation is a conundrum: we want people to be aware of Antarctica and concerned about what might happen there in the near future as climate changes. But hyping research results to sound like climate change, when they are just improved understanding of natural behaviour, is misleading.

Quote
Helen Amanda Fricker is a professor at the Scripps Institution of Oceanography
Title: Re: What's new in Antarctica ?
Post by: charles_oil on June 23, 2017, 11:06:21 PM

... and NSIDC shows Antarctic ice dropping to be the lowest recorded for the date today (June 22nd) by 44,000km2 !

Title: Re: What's new in Antarctica ?
Post by: Hyperion on June 29, 2017, 07:32:43 AM
1066 hpa.  How high can she go? Where she stops nobody knows. Theres even a stream of wet tropical air bombing straight down on EA.
https://earth.nullschool.net/#current/wind/isobaric/250hPa/overlay=mean_sea_level_pressure/orthographic=-268.28,-67.88,297/loc=104.055,-79.101
Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on July 03, 2017, 09:51:50 PM
The linked PBS article/video provides a convenient summary for beginners:

“Antarctica is melting faster than scientists expected”

http://www.pbs.org/newshour/bb/antarctica-melting-faster-scientists-expected/ (http://www.pbs.org/newshour/bb/antarctica-melting-faster-scientists-expected/)


Title: Re: What's new in Antarctica ?
Post by: wili on July 04, 2017, 02:03:23 PM

It’s Raining in Antarctica while Trump slashes Climate Science funding

 by Dahr Jamail at Truth-Out.
http://www.truth-out.org/news/item/41136-it-s-raining-in-antarctica-while-trump-slashes-climate-science-funding (http://www.truth-out.org/news/item/41136-it-s-raining-in-antarctica-while-trump-slashes-climate-science-funding)


Quote
parts of Antarctica are literally beginning to turn green, as scientists there are finding a four- to five-fold increase in the amount of moss growth on the ice continent's northern peninsula.

Even more stunning news comes from Antarctica in a study published in the June 15 issue of the journal Nature Communications which revealed that over an area of West Antarctica, scientists were stunned to find rainfall and a melt area larger than the size of Texas in 2016.

Yes, it is now raining in Antarctica.
Title: Re: What's new in Antarctica ?
Post by: gerontocrat on July 05, 2017, 01:51:56 PM
One thing Antarctica gives up is stunning images. Herewith cci-reanalyzer's image of the jet  stream.

Title: Re: What's new in Antarctica ?
Post by: sidd on July 05, 2017, 11:30:35 PM
Hillenbrand (2017) doi:10.1038/nature22995

"Here we present a multi-proxy data based reconstruction of variability in CDW inflow to the Amundsen Sea sector, the most vulnerable part of the West Antarctic Ice Sheet, during the Holocene epoch (from 11.7 thousand years ago to the present). The chemical compositions of foraminifer shells and benthic foraminifer assemblages in marine sediments indicate that enhanced CDW upwelling, controlled by the latitudinal position of the Southern Hemisphere westerly winds, forced deglaciation of this sector from at least 10,400 years ago until 7,500 years ago—when an ice-shelf collapse may have caused rapid ice-sheet thinning further upstream—and since the 1940s"

Nice paper. Ties right in to Smith (2017) doi:10.1038/nature20136

"Here we show that the present thinning and retreat of Pine Island Glacier in West Antarctica is part of a climatically forced trend that was triggered in the 1940s."

The last time PIG did this was 10K to 7.5K BP. Now if you look at Blanchon-2009, supplementary, you can see what the sea level was doing then. I attach fig s3.


sidd
Title: Re: What's new in Antarctica ?
Post by: Juan C. García on July 16, 2017, 11:36:18 PM
The linked PBS article/video provides a convenient summary for beginners:

“Antarctica is melting faster than scientists expected”

http://www.pbs.org/newshour/bb/antarctica-melting-faster-scientists-expected/ (http://www.pbs.org/newshour/bb/antarctica-melting-faster-scientists-expected/)

National Geographic: "The Larsen C Ice Shelf Collapse Is Just the Beginning—Antarctica Is Melting"

http://www.nationalgeographic.com/magazine/2017/07/antarctica-sea-level-rise-climate-change/ (http://www.nationalgeographic.com/magazine/2017/07/antarctica-sea-level-rise-climate-change/)
Title: Re: What's new in Antarctica ?
Post by: sidd on July 28, 2017, 10:08:15 PM
Two papers by Golledge et al, one dealing with Pliocene Antarctica, and the other with EAIS vulnerabilities. The first has a discussion of tipping points in the Pliocene through autocorrelation and variance analysis and some discussion of critical slowing down. The second indicates that the Recovery basin is most vulnerable to Weddel se warming.

Read all about it.

doi:10.5194/cp-13-959-2017

doi:10.1002/2016GL072422

sidd
Title: Re: What's new in Antarctica ?
Post by: Lennart van der Linde on July 31, 2017, 07:45:29 AM
Thanks, sidd.

Golledge et al 2017 on Pliocene say in their abstract:
https://www.clim-past.net/13/959/2017/ (https://www.clim-past.net/13/959/2017/)

"we investigate how Antarctica evolved under orbital and greenhouse gas conditions representative of an interglacial in the early Pliocene at 4.23 Ma, when Southern Hemisphere insolation reached a maximum. Using offline-coupled climate and ice-sheet models, together with a new synthesis of high-latitude palaeoenvironmental proxy data to define a likely climate envelope, we simulate a range of ice-sheet geometries and calculate their likely contribution to sea level. In addition, we use these simulations to investigate the processes by which the West and East Antarctic ice sheets respond to environmental forcings and the timescales over which these behaviours manifest. We conclude that the Antarctic ice sheet contributed 8.6 ± 2.8 m to global sea level at this time, under an atmospheric CO2 concentration identical to present (400 ppm). Warmer-than-present ocean temperatures led to the collapse of West Antarctica over centuries, whereas higher air temperatures initiated surface melting in parts of East Antarctica that over one to two millennia led to lowering of the ice-sheet surface, flotation of grounded margins in some areas, and retreat of the ice sheet into the Wilkes Subglacial Basin. The results show that regional variations in climate, ice-sheet geometry, and topography produce long-term sea-level contributions that are non-linear with respect to the applied forcings, and which under certain conditions exhibit threshold behaviour associated with behavioural tipping points."
Title: Re: What's new in Antarctica ?
Post by: Lennart van der Linde on July 31, 2017, 07:55:36 AM
Golledge et al 2017 on Weddell say:
http://sci-hub.cc/10.1002/2016GL072422 (http://sci-hub.cc/10.1002/2016GL072422)

"we use an ensemble of idealized climates to drive ice-sheet simulations that explore regional and continental-scale thresholds, allowing us to identify a hierarchy of catchment vulnerabilities based on differences in long-term catchment-averaged ice loss. Considering this hierarchy in the context of recent observations and climate scenarios forecast for 2100 CE we conclude that the majority of future ice loss from East Antarctica, both this century and over subsequent millennia, will likely come from the Recovery subglacial basin in the eastern Weddell Sea."
Title: Re: What's new in Antarctica ?
Post by: bairgon on August 13, 2017, 07:43:46 AM
Guardian article: "Scientists discover 91 volcanoes below Antarctic ice sheet"

https://www.theguardian.com/world/2017/aug/12/scientists-discover-91-volcanos-antarctica (https://www.theguardian.com/world/2017/aug/12/scientists-discover-91-volcanos-antarctica)

Quote
Scientists have uncovered the largest volcanic region on Earth – two kilometres below the surface of the vast ice sheet that covers west Antarctica.

The project, by Edinburgh University researchers, has revealed almost 100 volcanoes – with the highest as tall as the Eiger, which stands at almost 4,000 metres in Switzerland.
Title: Re: What's new in Antarctica ?
Post by: Dry_Land_Is_Not_A_Myth on August 15, 2017, 04:33:45 AM
Title: Thirty Years After the Montreal Protocol, Solving the Ozone Problem Remains Elusive

Summary: "Despite a ban on chemicals like chlorofluorocarbons, the ozone hole over Antarctica remains nearly as large as it did when the Montreal Protocol was signed in 1987. Scientists now warn of new threats to the ozone layer, including widespread use of ozone-eating chemicals not covered by the treaty."

Meat:
" [DCM (dichloromethane)] it has not been regarded as a threat to the ozone layer, because its typical lifetime in the atmosphere before it is broken down in photochemical reactions is only about five months. It should, atmospheric chemists concluded, remain safely in the lower atmosphere...But that view collapsed"

"DCM...could delay the ozone hole’s recovery by 30 years, until at least 2095"

http://e360.yale.edu/features/thirty-years-after-the-montreal-protocol-solving-the-ozone-problem-remains-elusive (http://e360.yale.edu/features/thirty-years-after-the-montreal-protocol-solving-the-ozone-problem-remains-elusive)

Personal thoughts : Is UV radiation, and its predicted diminishing flux, taken into the modeling of Antarctica ice stability? If so, this summary suggests that this factor will remain stronger longer than expected.
Title: Re: What's new in Antarctica ?
Post by: Daniel B. on August 15, 2017, 03:27:12 PM
Most data shows a lessening of the Antarctic ozone hole, continuing throught this century.  The hole will still fluctuate based on the extent of winter temperatures.

https://www.nature.com/articles/s41598-017-00722-7 (https://www.nature.com/articles/s41598-017-00722-7)

https://www.epa.gov/ozone-layer-protection/current-state-ozone-layer (https://www.epa.gov/ozone-layer-protection/current-state-ozone-layer)

https://www.nasa.gov/feature/Goddard/2016/antarctic-ozone-hole-attains-moderate-size (https://www.nasa.gov/feature/Goddard/2016/antarctic-ozone-hole-attains-moderate-size)

https://www.sciencenews.org/article/antarctica-ozone-hole-top-science-stories-2016 (https://www.sciencenews.org/article/antarctica-ozone-hole-top-science-stories-2016)

Title: Re: What's new in Antarctica ?
Post by: Juan C. García on October 12, 2017, 10:26:06 PM
Washington Post -
Worrying new research finds that the ocean is cutting through a key Antarctic ice shelf

Quote
The new study calculates that as a result of this highly uneven melting, the Dotson ice shelf could be melted all the way through in 40 years, rather than 170 years, which would be the time it would take if the melt were occurring evenly. And it speculates that as the thinning continues, the shelf may not go quietly or steadily any longer — something dramatic could occur, such as a breakup.

https://www.washingtonpost.com/news/energy-environment/wp/2017/10/11/alarming-new-research-finds-that-the-ocean-is-cutting-through-a-key-antarctic-ice-shelf/?utm_term=.da94284bfb0f&wpisrc=nl_green&wpmm=1 (https://www.washingtonpost.com/news/energy-environment/wp/2017/10/11/alarming-new-research-finds-that-the-ocean-is-cutting-through-a-key-antarctic-ice-shelf/?utm_term=.da94284bfb0f&wpisrc=nl_green&wpmm=1)
Title: Re: What's new in Antarctica ?
Post by: logicmanPatrick on October 13, 2017, 12:33:09 AM
Hole the Size of Maine Opens in Antarctica Ice

http://news.nationalgeographic.com/2017/10/sea-ice-hole-antarctica-southern-ocean-spd/?utm_source=Twitter&utm_medium=Social&utm_content=link_tw20171011news-icehole&utm_campaign=Content&sf121110519=1 (http://news.nationalgeographic.com/2017/10/sea-ice-hole-antarctica-southern-ocean-spd/?utm_source=Twitter&utm_medium=Social&utm_content=link_tw20171011news-icehole&utm_campaign=Content&sf121110519=1)
Title: Re: What's new in Antarctica ?
Post by: Shared Humanity on October 13, 2017, 06:01:09 PM
Other articles on Dotson ice shelf.

http://www.iflscience.com/environment/an-upsidedown-ice-canyon-in-antarctica-is-slicing-through-an-ice-shelf/ (http://www.iflscience.com/environment/an-upsidedown-ice-canyon-in-antarctica-is-slicing-through-an-ice-shelf/)

http://www.iflscience.com/environment/an-upsidedown-ice-canyon-in-antarctica-is-slicing-through-an-ice-shelf/ (http://www.iflscience.com/environment/an-upsidedown-ice-canyon-in-antarctica-is-slicing-through-an-ice-shelf/)

https://www.livescience.com/60662-upside-down-canyon-antarctic-ice-underside.html (https://www.livescience.com/60662-upside-down-canyon-antarctic-ice-underside.html)
Title: Re: What's new in Antarctica ?
Post by: bligh8 on October 15, 2017, 02:35:57 AM
Penguin catastrophe leaves thousands of chicks dead with only two survivors

“A penguin colony in Antarctica has suffered a massive breeding failure, with only two chicks surviving the disaster.
Terre Adélie (Adélie Land) is home to more than 18,000 pairs of Adélie penguins, but this year almost all the seabirds' babies starved to death, a situation one expert described as "Tarantino does Happy Feet."
The World Wildlife Fund said unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food.”

“Last year, research by oceanographers at the University of Delaware found that 60% of Antarctica's Adélie penguin habitat may become unsuitable for the birds by the end of the 21st century, because of warming seas and rain.”

That statement seems a rather optimistic remark.

http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html (http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html)
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on November 07, 2017, 09:18:39 PM
Don't know if  this is the right place to put this, but in my usual looksee at global temps and patterns at Nullschool, I noticed a number of above freezing temperatures and incursions at the West Antarctic peninsula. I assume this is likely for the time of year, (Nov = May in NH?) but it seemed to be worth sharing. Click for spot temperatures (those greens).
https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-54.33,-82.99,568 (https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-54.33,-82.99,568)
Title: Re: What's new in Antarctica ?
Post by: Shared Humanity on November 08, 2017, 04:27:48 PM
Don't know if  this is the right place to put this, but in my usual looksee at global temps and patterns at Nullschool, I noticed a number of above freezing temperatures and incursions at the West Antarctic peninsula. I assume this is likely for the time of year, (Nov = May in NH?) but it seemed to be worth sharing. Click for spot temperatures (those greens).
https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-54.33,-82.99,568 (https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-54.33,-82.99,568)

Not good given the current state of Larsen C ice shelf.
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on November 08, 2017, 05:01:21 PM
Interested parties might like to go over to Larsen C article for some gorgeous (depending on how you define gorgeous, if danger can be beautiful) visuals SharedHumanity provided from ClimateReanalyzer (above my trivial response): https://forum.arctic-sea-ice.net/index.php/topic,1175.200.html#lastPost (https://forum.arctic-sea-ice.net/index.php/topic,1175.200.html#lastPost)
Title: Re: What's new in Antarctica ?
Post by: FredBear on November 09, 2017, 12:24:52 PM
In arctic io (08.11.17) ( http://www.arctic.io/explorer/4Xa5A//4-N90-E0 ) above the Brunt ice shelf is large white quadrilateral iceberg which has been rotating along the coastline as it has been moving westward - it may be worth watching to see if it has any effect on Brunt if/when it passes? I saw it travelling last summer and it was frozen into the winter ice just above its present location, with the ice freeing it around 12-14.10.17. (It was above Georg von Neumayer Station on 29.03.2017)
Title: Re: What's new in Antarctica ?
Post by: Daniel B. on November 09, 2017, 03:48:58 PM
Penguin catastrophe leaves thousands of chicks dead with only two survivors

“A penguin colony in Antarctica has suffered a massive breeding failure, with only two chicks surviving the disaster.
Terre Adélie (Adélie Land) is home to more than 18,000 pairs of Adélie penguins, but this year almost all the seabirds' babies starved to death, a situation one expert described as "Tarantino does Happy Feet."
The World Wildlife Fund said unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food.”

“Last year, research by oceanographers at the University of Delaware found that 60% of Antarctica's Adélie penguin habitat may become unsuitable for the birds by the end of the 21st century, because of warming seas and rain.”

That statement seems a rather optimistic remark.

http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html (http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html)

That statements seems rather odd and in contrast to the rest of the article.  The article stated that "unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food."  Would it not follow that "warming seas and rain" would result in less extensive amounts of sea, allowing the penguins to travel less than normal?
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on November 09, 2017, 04:21:58 PM
@FredBaer: your image is of the Arctic. Did you mean to put that here with Antarctica?
Title: Re: What's new in Antarctica ?
Post by: Ajpope85 on November 09, 2017, 06:07:10 PM
Penguin catastrophe leaves thousands of chicks dead with only two survivors

“A penguin colony in Antarctica has suffered a massive breeding failure, with only two chicks surviving the disaster.
Terre Adélie (Adélie Land) is home to more than 18,000 pairs of Adélie penguins, but this year almost all the seabirds' babies starved to death, a situation one expert described as "Tarantino does Happy Feet."
The World Wildlife Fund said unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food.”

“Last year, research by oceanographers at the University of Delaware found that 60% of Antarctica's Adélie penguin habitat may become unsuitable for the birds by the end of the 21st century, because of warming seas and rain.”

That statement seems a rather optimistic remark.

http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html (http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html)

That statements seems rather odd and in contrast to the rest of the article.  The article stated that "unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food."  Would it not follow that "warming seas and rain" would result in less extensive amounts of sea, allowing the penguins to travel less than normal?

I don't know if this is the case here, but fresh water has a higher freezing point than sea water and if it's raining, then that fresh water and melting ice water can flow into the ocean and freeze when it hits the cooler ocean water.
Title: Re: What's new in Antarctica ?
Post by: Daniel B. on November 09, 2017, 06:52:16 PM
Penguin catastrophe leaves thousands of chicks dead with only two survivors

“A penguin colony in Antarctica has suffered a massive breeding failure, with only two chicks surviving the disaster.
Terre Adélie (Adélie Land) is home to more than 18,000 pairs of Adélie penguins, but this year almost all the seabirds' babies starved to death, a situation one expert described as "Tarantino does Happy Feet."
The World Wildlife Fund said unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food.”

“Last year, research by oceanographers at the University of Delaware found that 60% of Antarctica's Adélie penguin habitat may become unsuitable for the birds by the end of the 21st century, because of warming seas and rain.”

That statement seems a rather optimistic remark.

http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html (http://www.cnn.com/2017/10/13/world/antarctica-penguin-chicks-die/index.html)

That statements seems rather odd and in contrast to the rest of the article.  The article stated that "unseasonably extensive amounts of sea ice around the colony in East Antarctica had forced the adult penguins to travel further than normal to forage for food."  Would it not follow that "warming seas and rain" would result in less extensive amounts of sea, allowing the penguins to travel less than normal?

I don't know if this is the case here, but fresh water has a higher freezing point than sea water and if it's raining, then that fresh water and melting ice water can flow into the ocean and freeze when it hits the cooler ocean water.

Maybe, but it seems more likely that the rain would freeze on the colder ice, than the warmer salt water.  Whatever the case, I do not see many projections of expanding sea ice around Antarctica in the coming decades.
Title: Re: What's new in Antarctica ?
Post by: FredBear on November 09, 2017, 07:32:15 PM
@FredBaer: your image is of the Arctic. Did you mean to put that here with Antarctica?
Sorry, I forgot arctic io reverts back to the Arctic, you have to use the drop-down menu on the right, select Antarctica, then add names, then zoom in on the appropriate part of the Weddell Sea. (I don't know how to lift images from the site - and also cannot find the code for the icebergs so I do not know where it originated.)
Title: Re: What's new in Antarctica ?
Post by: johnm33 on November 10, 2017, 10:16:53 AM
Brunt image (https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2017/imagethehall.jpg) expandable, from https://phys.org/news/2017-10-image-halloween-antarctica-brunt-ice.html
Title: Re: What's new in Antarctica ?
Post by: charles_oil on November 10, 2017, 11:23:58 AM
Is "New Base" on the map where they plan to get to next ?
Title: Re: What's new in Antarctica ?
Post by: FredBear on November 10, 2017, 12:02:41 PM
"New Base" is where they parked Halley VI last year    .    .   .   then twitched about the Halloween crack to the east ('above' in the images). Halloween crack seems to show up on (ant)arctic io for 2017.11.04.
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on November 10, 2017, 09:54:13 PM
Thanks for explaining FredBaer, I'll try that.

Moving on ...
I've been wanting to post this but was trying to figure out how to make the image smaller using html without success. The simple image editor on the older Macs is gone, and I want to post this without further delay, so I'll come back and fix it later, meanwhile, people can click on it to see the whole thing.

Being a true amateur, I flounder around a bit. I don't know how helpful this might be to anyone, but it just popped up recently via Wunderground comments:
Hot News from the Antarctic Underground NASA Jet Propulsion Lab https://www.jpl.nasa.gov/news/news.php?release=2017-291 (https://www.jpl.nasa.gov/news/news.php?release=2017-291)

(https://www.jpl.nasa.gov/images/earth/20171107/Antarctic-volcano-16.jpg)
Quote
Study Bolsters Theory of Heat Source Under West Antarctica

A new NASA study adds evidence that a geothermal heat source called a mantle plume lies deep below Antarctica's Marie Byrd Land, explaining some of the melting that creates lakes and rivers under the ice sheet. Although the heat source isn't a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today.

Title: Re: What's new in Antarctica ?
Post by: charles_oil on November 11, 2017, 02:23:32 PM
Thanks Fred - seems odd they saw and marked the tracks from the earlier VI location -  wonder where next !
Title: Re: What's new in Antarctica ?
Post by: Shared Humanity on November 11, 2017, 03:26:18 PM
Thanks for link Susan.
Title: Re: What's new in Antarctica ?
Post by: solartim27 on November 16, 2017, 05:21:02 PM
What's new is actually very old
https://relay.nationalgeographic.com/proxy/distribution/public/amp/2017/11/ancient-fossil-forest-found-antarctica-gondwana-spd
Title: Re: What's new in Antarctica ?
Post by: Grygory on November 16, 2017, 09:08:20 PM
What do you think about this photo (Ross Ice shelf)? - Is a new iceberg created?
http://www.polarview.aq/images/105_S1jpgfull/S1B_EW_GRDM_1SDH_20171115T112359_75CF_S_1.final.jpg
Sorry if this is not the topic
Title: Re: What's new in Antarctica ?
Post by: sidd on December 12, 2017, 01:05:06 AM
Reese et al on vulnerable spots for ice shelf thinning:

doi: 10.1038/s41558-017-0020-x

This is a theoretical study using finite element analysis, so awaits validation by observation. They find that there are certain spots on ice shelves, that when thinned, induce flow acceleration of grounded ice hundreds of kilometers away. They characterize the vulnerability by a "response ratio " . This is " the ratio between the total changes in annual mass flux across all grounding lines to the magnitude of locally applied thinning"

I attach fig 1d showing the Amundsen Sea region. Black is a ratio of 100%

sidd
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on December 21, 2017, 06:29:02 AM
Very beautiful short flick here, I suspended my usual attitudes and questions and just enjoyed it. Lovely music, and I recommend putting it on full screen (source: my weekly Earth Observatory Newsletter which has all sorts of other goodies in it: https://earthobservatory.nasa.gov/ )

https://www.youtube.com/watch?v=_LnH5fx5nyk

There are some interesting and odd things on the youtube collection as well.
Title: Re: What's new in Antarctica ?
Post by: sidd on December 23, 2017, 12:05:18 AM
Campbell et al. have an unsettling result about the Ross shelf. Apparently it will continue thinning this century even absent ocean warming. This is an analysis using surface heights from GLAS and IceSAT and but all they say about the ice model is that it is a "well-tested numerical model of ice shelf flow that simulates both mass and momentum balance responses to various forcings on the ice shelf."

I wonder which one it is.

doi: 10.1002/2017GL075794

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on December 23, 2017, 08:22:16 AM
In the light of Mercer's warning i look at 0C in antarctica around the solstice in december. So i did today. PIG/Thwaites and Amery-Holmes seem around freezing.

Amery has been worrying me for a long time.

sidd
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on December 25, 2017, 09:15:35 PM
I'm curious as to what is happening with east Antarctica. As I often do, I've been looking at Nullschool - https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=328.21,-93.13,569 (https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=328.21,-93.13,569) - and there appears to be quite a bit of warming in the area I think is in the area of Davis Sea and Enderby Land http://nsidc.org/arcticseaicenews/files/2014/07/antarctica_locator_map_nbv_20170213-1002x1024.png (http://nsidc.org/arcticseaicenews/files/2014/07/antarctica_locator_map_nbv_20170213-1002x1024.png)

Is that unusual or is it because summer is really getting starting at the south pole?
Title: Re: What's new in Antarctica ?
Post by: sidd on January 04, 2018, 09:13:43 AM
This post could easily belong on many threads, but i post here because it is a new and beautiful result from WAIS divide ice core. Bereiter et al. have produced a record of mean ocean temperature since the last deglaciation from isotope fractions of noble gases. The timespan is  from 24 kyr. to 7.5 kyr and from 4 Kyr to present. The unfortunate data gap is due to sample rejection. Over most of the data the time resolution is 250 yr.

In the quotes below MOT is mean ocean temperature, LGM is last glacial maximum

"It is interesting to note that since the LGM about the same amount of energy has gone into MOT as into melting grounded ice (Fig. 3b). This is not contradicting the understanding that most of the current anthropogenic warming has been taken up by the ocean ..."

"The warming from 12,750 yr bp to 12,050 yr bp (referred to as YD1) within the Younger Dryas represents the strongest global ocean warming phase within our record. The MOT change rate is 2.5 ± 0.53 mK yr −1 and the corresponding energy uptake (13.8 ± 2.9) × 1e21  J/yr. This unprecedented natural MOT warming rate is comparable to the strong warming since 1997 estimated in ref. 1, but clearly surpasses the estimate therein for the multidecadal trend from 1971 to 2005 ..."

I attach fig 2 because the data shows the pretty agreement between all the different isotope ratio estimates.  I also attach panel a) from fig 3 showing ocean heat uptake. The dashed vertical lines in Fig 3a are the same as in Fig 2 althoug the timescale is from 22 kyr to 7.5 kyr BP (before present, where "present" is taken to mean 1950)

doi: 10.1038/nature25152

sidd

Title: Re: What's new in Antarctica ?
Post by: AbruptSLR on January 09, 2018, 05:33:15 PM
For your edification:

Zhao, L., Moore, J. C., Sun, B., Tang, X., and Guo, X.: Where is the 1-million-year-old ice at Dome A?, The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-269, in review, 2018.

https://www.the-cryosphere-discuss.net/tc-2017-269/

Abstract. Ice fabric influences the rheology of ice, and hence the age/depth profile at ice core drilling sites. We use the depth varying anisotropic fabric suggested by the recent polarimetric measurements around Dome A along with prescribed fabrics ranging from isotropic through girdle to single maximum in a three-dimensional, thermo-mechanically coupled full-Stokes model of a 70 × 70 km2 domain around Kunlun station. This model allows to simulate the near basal ice temperature and age, and ice flow around the location of the Chinese deep ice coring site. Ice fabrics and geothermal heat flux strongly affect the vertical advection and basal temperature which in consequence controls the age profile. Constraining modeled age-depth profiles with dated radar isochrones to 2/3 ice depth, the surface vertical velocity, and also the spatial variability of a radar isochrones dated to 153.3 kyr BP, limits the age of the deep ice at Kunlun to 649–831 kyr, a much smaller range than inferred previously. The simple interpretation of the polarmetric radar fabric data that we use produces best fits with a geothermal heat flux of 55 mWm−2. A heat flux of 50 mWm−2 is too low to fit the deeper radar layers, and a heat flux of 60 mWm−2 leads to unrealistic surface velocities. The modeled basal temperature at Kunlun reaches the pressure melting point with a basal melting rate of 2.2–2.7 mm yr−1. Using the spatial distribution of basal temperatures and the best fit fabric suggests that within 400 m of Kunlun station, 1 million-year old ice may be found 200 m above the bed, and there are large regions where even older ice is well above the bedrock within 1–2 km of the Kunlun station.
Title: Re: What's new in Antarctica ?
Post by: Tealight on January 14, 2018, 02:12:59 AM
Edit: The small part was actually sea ice and not part of the ice shelf anymore. The part just hasn't broken off so early in the melting season before or sometimes didn't become ice-free at all.


Nasa Worldview Link: https://go.nasa.gov/2FCpa1R
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on January 14, 2018, 09:56:44 PM
Fascinating, if scary. Combined with what is going on with PIG (https://forum.arctic-sea-ice.net/index.php/topic,429.msg138777.html#new (https://forum.arctic-sea-ice.net/index.php/topic,429.msg138777.html#new)), a southern "summer" to remember.
Title: Re: What's new in Antarctica ?
Post by: Gray-Wolf on January 15, 2018, 12:00:58 PM
I've been monitoring a huge crack that runs from roosevelt into the centre of the shelf. I spoke with McMurdo back in 09' and they were then putting sensors along the feature to monitor development. This calve opens up the Roosevelt Island end of that fissure
https://worldview.earthdata.nasa.gov/?p=antarctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2017-12-14&z=3&v=-429312,-1278080,-79616,-1115008
and so may lead to further stresses as the ocean accesses the base there ( if the grounding line is not already there?).
Title: Re: What's new in Antarctica ?
Post by: FredBear on January 15, 2018, 04:20:41 PM
Gray-Wolf: There is also the 'loose tooth' berg half way along the Ross shelf (is it the 'ice' in current nsidc Antarctic maps - I cannot see any sea ice there?), and some fraying of the shelf at the Mt. Erebus end too. The "coastline" marking shows how much the shelf has advanced since (?). Recently nsidc sea ice extent has been trying to catch up (down!) with last year too. Jan 14 2018 view:-

https://worldview.earthdata.nasa.gov/?p=antarctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2018-01-14&z=3&v=-689065.3881177683,-1434110.2019443244,-339369.38811776834,-1236560.9422758163
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 16, 2018, 04:56:49 PM
A nice series of pictures and videos from the Swiss Polar Institutes circumnavigation expedition in early 2017.
https://interactive.aljazeera.com/aje/2017/antarctica-voyage/index.html#11
Title: Re: What's new in Antarctica ?
Post by: Yuha on January 16, 2018, 08:38:38 PM
A nice series of pictures and videos from the Swiss Polar Institutes circumnavigation expedition in early 2017.
https://interactive.aljazeera.com/aje/2017/antarctica-voyage/index.html#11

Fascinating, well worth the time to watch it through. Some highlights:
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on January 16, 2018, 09:16:00 PM
A nice series of pictures and videos from the Swiss Polar Institutes circumnavigation expedition in early 2017.
https://interactive.aljazeera.com/aje/2017/antarctica-voyage/index.html#11

Fascinating, well worth the time to watch it through. Some highlights:

  • Rotten ice under Mertz glacier
  • A brittle star catching a living fish, which has never been observed before.

Indeed, amazing ... takes a while, do view all of it!
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 19, 2018, 04:03:23 PM
Just a background article on a core drilling expedition on the Ross sea, JOIDES

http://blogs.discovermagazine.com/crux/2018/01/18/antarctica-melted-joides/

Quote
Over the next couple months, their ship, the International Ocean Discovery Program’s JOIDES Resolution, will drill at least five core samples reaching thousands of feet below the Ross Sea. These cores will let scientists read layers in the rock record like pages of a book, unraveling climate and ice conditions stretching back tens of millions of years.

Twitter account:  https://mobile.twitter.com/TheJR

Expedition blog:  http://joidesresolution.org/first-core-on-deck-2/
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 19, 2018, 05:23:56 PM
A nice satellite shot of the USCG icebreaker Polar Star heading to Mcmurdo station
From: https://mobile.twitter.com/peter_neff/status/953857709450805249
Title: Re: What's new in Antarctica ?
Post by: solartim27 on January 19, 2018, 05:31:04 PM
Another nice Landsat 8 pic of meltwater
From:  https://mobile.twitter.com/StefLhermitte/status/952996849128017923
And:  https://mobile.twitter.com/AntarcticReport/status/954329004105900032
Quote
More mid-summer surface water, this time on King Baudouin Ice Shelf, Dronning Maud Land, East #Antarctica. Landsat 8 satellite image includes "englacial" lakes, i.e. sandwiched between surface of the ice shelf and its base floating on the ocean beneath @NASA_Landsat @USGSLandsat
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on January 19, 2018, 09:59:21 PM
@Solartim27

That looks a bit like Larsen B just before it broke up.
https://earthobservatory.nasa.gov/Features/WorldOfChange/larsenb.php (https://earthobservatory.nasa.gov/Features/WorldOfChange/larsenb.php)
Title: Re: What's new in Antarctica ?
Post by: charles_oil on January 28, 2018, 07:39:42 PM

Interesting short video on CNN about robots being used in a year-long study under the Antarctic ice.


https://edition.cnn.com/2018/01/27/world/antarctica-ice-robots/index.html



Scientists with the University of Washington in conjunction with Paul G. Allen Philanthropies are sending robots to Antarctica for as long as a year in what will be the longest mission ever undertaken in the region.
The aim: to gain more extensive data about the rate of ice loss and thus more accurately predict future sea-level rise.
Navigation algorithms enable the Seaglider robots to maneuver autonomously.
The autonomous underwater gliders move by changing their buoyancy, rising to the surface to transmit data, and that comes with a risk -- some may sink and be lost for good as they move under the Antarctic ice sheets.

It's a small price to pay when talking about the fate of the world, according to a spokesman for Microsoft co-founder and investor Paul Allen, who has funded the mission.
Title: The 2041 SPEC trek to the South Pole
Post by: Jim Hunt on February 02, 2018, 12:45:53 PM
Slightly belated news that on January 15th the father and son team of Robert and Barney Swan reached the South Pole after a 56 day trek powered entirely by renewable energy:

https://www.2041.com/blog/father-and-son-at-the-pole-day-56-of-spec/

Shell were one of the expedition's sponsors:

http://youtu.be/uyvNg43NdFE
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on February 03, 2018, 07:07:06 PM
Warmth being pushed south toward Antarctica at speed today (roughly, Feb = August north of equator).
https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-53.48,-77.19,317 (https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=-53.48,-77.19,317)
---
Thanks for posting that, Jim.
Title: Re: What's new in Antarctica ?
Post by: solartim27 on February 06, 2018, 07:15:20 PM
I'm not sure how useful this may be, but it looks interesting,  and it's free.
http://www.npolar.no/en/news/2018/02-06-relansering-av-Quantarctica.html
Quote
Version 3 of the Quantarctica mapping tool is released today.
Quantarctica is a free package of scientific and geographic datasets for Antarctica. Version 3 now includes data from ten different scientific themes, increased from just two in version 2.

An international team of scientific editors was also recruited to Quantarctica's Editorial Board, and helped review and evaluate datasets to represent their fields in Quantarctica.



Title: Re: What's new in Antarctica ?
Post by: sidd on February 11, 2018, 06:27:35 AM
Nice paper by Snow et al. on changes in bottom water after a caving event in Adelie Land. After the calving Deep Shelf Water freshened resulting in not just fresher, but warmer Bottom Water. This is one of the few results from in situ measurements at the bottom of the world, covering a period from 1994 to 2015.

I attach Fig3a and fig S1. The y axis on the former is density, and Fig S1 shows the process that warms and freshens Bottom Water.

sidd
Title: Re: What's new in Antarctica ?
Post by: ivica on February 22, 2018, 11:34:41 AM

https://www.nasa.gov/feature/jpl/new-study-brings-antarctic-ice-loss-into-sharper-focus

Quote
“We’re entering a new age,” said the study’s lead author, cryospheric researcher Alex Gardner of NASA’s Jet Propulsion Laboratory in Pasadena, California. “When I began working on this project three years ago, there was a single map of ice sheet flow that was made using data collected over 10 years, and it was revolutionary when it was published back in 2011. Now we can map ice flow over nearly the entire continent, every year. With these new data, we can begin to unravel the mechanisms by which the ice flow is speeding up or slowing down in response to changing environmental conditions.”

(https://www.nasa.gov/sites/default/files/thumbnails/image/antarctic20180220-16.jpg)

Earth Research Findings, Feb. 20, 2018
Title: Re: What's new in Antarctica ?
Post by: sidd on February 22, 2018, 09:09:32 PM
The Gardner paper is nice. From the table 1) i see that basins 20,21,22 (include thwaites) are showing increases in mass loss of the order of 5-7%. If I were to buy into Hansen's exponential increas picture, thats a doubling time of 10-15 yrs. We shall see.

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on February 24, 2018, 10:06:00 PM
edit: My last post is erroneous:  The mass loss in Table 1 is for the periods 2008-2015, 7 years. So the increase is 5-7% over seven years, say 1% a year, for  doubling time of 70 years

sidd
Title: Re: What's new in Antarctica ?
Post by: FredBear on March 02, 2018, 01:25:46 PM
Quite a chunk of 1 y.old sea ice is breaking away in the S.E. corner of the Weddell Sea in the last few days. There seems to be off-shore winds blowing new sea ice away from the continent in many places.
The off-shore ice in front of Thwaites has also been fracturing & moving out a little since late February.
Title: Re: What's new in Antarctica ?
Post by: sidd on March 03, 2018, 02:56:45 AM
Nias et al. have a new bedrock fit to PIG:

doi: 10.1002/2017GL076493

Apparenty a modelled rise near the grounding line may not exist, and affects features a very long way upstream.

"Subtle variation in the geometry near the grounding line can trigger a response in the ice sheet that is felt hundreds of kilometers upstream."

sidd
Title: Re: What's new in Antarctica ?
Post by: Hyperion on March 16, 2018, 08:43:57 AM
Hot core fully eyewalled up tropical cyclones raging around the coast of Antarctica.
Title: Re: What's new in Antarctica ?
Post by: Grygory on March 20, 2018, 11:08:24 AM
New crack in Ross ice Shelf?- I am wrong?
https://postimg.org/image/wckqa96zv/
Title: Re: What's new in Antarctica ?
Post by: sidd on April 02, 2018, 10:25:15 PM
This paper has been posted in another thread, but i include it here: Konrad et al., "Net retreat of Antarctic glacier grounding lines"

doi: 10.1038/s41561-018-0082-z

Apparently PIG has slowed, but Thwaites retreats faster:

"At Thwaites Glacier, the average rate of grounding-line retreat has increased from 340  ±​ 280 m yr −1
between 1996 and 2011-12 to 420  ±​ 240 m ..."

"Retreat at Pine Island Glacier appears to have stagnated at 40 m yr −1  ±​ 30 m yr −1 during the CryoSat-2 period, after it migrated inland at a rate of around 1,000 m yr −1 between 1992 and 2011"

"This leads us to conclude that the main trunk’s grounding line has stabilized, potentially due to the absence of warm sub-shelf water 36 that drove retreat until 2011."

Elsewhere, retreat proceeds apace:

" ... high local rates of retreat of ~1,200 m/yr in our results on Haynes, Smith and Kohler glaciers are comparable to peak rates of 1,800 to 2,000 m/yr detected by InSAR between 1992 and 2014 [12,15] . In the Bellingshausen Sea, slower rates of retreat recorded over the last 40 years [13] are similar to those we have derived: at Ferrigno Ice Stream, rates of retreat remain in the range of 50 to 200 m/yr ; at Lidke Glacier, Berg Ice Stream and Venable and Abbot ice shelves, our rates of retreat are in the range of 10 to 40 m/yr in accordance with the multi-decadal range of 10 to 90 m/yr (ref.  13 ); and at the Cosgrove Ice Shelf, we detect no significant retreat, in agreement with previously observed rates between −​40 m/yr and +​11 m/yr (ref.  13 ). In East Antarctica, Totten Glacier is the only location where grounding-line retreat has been documented, and our result of 154 m/yr  ±​ 24 m/yr retreat in its fast-flowing section is consistent with the maximum rate of 176 m/yr recorded between 1996 and 2013 [14] ."

I attach fig 1.

sidd


Title: Re: What's new in Antarctica ?
Post by: Tealight on April 03, 2018, 12:57:03 AM
I found some great high quality videos of helicopter flights over the McMurdo Dry Valleys. No satellite can ever reach this detail.

First video is from Scott Base to Mt JJ Thomson:
https://youtu.be/qVfvvJB7g1g

You can also try to follow the flight path on worldview on a second screen:
https://go.nasa.gov/2uCmXBO
Title: Re: What's new in Antarctica ?
Post by: miki on April 03, 2018, 05:17:15 PM
Antarctica's Underwater Ice Is Retreating 5 Times Faster Than It Should Be

https://www.livescience.com/62203-antarctica-underwater-ice-loss.html

"In the new study, Hannes and his colleagues at the Centre for Polar Observation and Modelling (CPOM) at the University of Leeds used a combination of satellite imagery and buoyancy equations to map out the invisible retreat of underwater ice across roughly 10,000 miles (16,000 kilometers) of Antarctica's coastlines — roughly one-third of the continent's total perimeter."

*****************************

Antarctica 'gives ground to the ocean'

http://www.bbc.com/news/science-environment-43627673

"Scientists now have their best view yet of where Antarctica is giving up ground to the ocean as some its biggest glaciers are eaten away from below by warm water."

*****************************

Net retreat of Antarctic glacier grounding lines

Hannes Konrad1,2*, Andrew Shepherd1, Lin Gilbert3, Anna E. Hogg1, Malcolm McMillan1, Alan Muir3 and Thomas Slater1

https://www.nature.com/articles/s41561-018-0082-z.epdf

Grounding lines are a key indicator of ice-sheet instability, because changes in their position reflect imbalance with the surround-ing ocean and affect the flow of inland ice. Although the grounding lines of several Antarctic glaciers have retreated rapidly due to ocean-driven melting, records are too scarce to assess the scale of the imbalance. Here, we combine satellite altimeter observations of ice-elevation change and measurements of ice geometry to track grounding-line movement around the entire continent, tripling the coverage of previous surveys. Between 2010 and 2016, 22%, 3% and 10% of surveyed grounding lines in West Antarctica, East Antarctica and at the Antarctic Peninsula retreated at rates faster than 25 m yr−1 (the typical pace since the Last Glacial Maximum) and the continent has lost 1,463 km2 ±  791 km2 of grounded-ice area. Although by far the fastest rates of retreat occurred in the Amundsen Sea sector, we show that the Pine Island Glacier grounding line has stabilized, probably as a consequence of abated ocean forcing. On average, Antarctica’s fast-flowing ice streams retreat by 110 metres per metre of ice thinning.
Title: Re: What's new in Antarctica ?
Post by: RoxTheGeologist on April 09, 2018, 03:25:27 PM

Antarctic snow fall has since an increase since 2000 - interesting as they measure 200 years of yearly snowfails.

http://www.bbc.com/news/science-environment-43691671
Title: Re: What's new in Antarctica ?
Post by: Daniel B. on April 09, 2018, 04:48:20 PM
Results from the New Zealand team's bore hole through the Ross shelf show ice growth.

https://news.nationalgeographic.com/2018/02/ross-ice-shelf-bore-antarctica-freezing/ (https://news.nationalgeographic.com/2018/02/ross-ice-shelf-bore-antarctica-freezing/)
Title: Re: What's new in Antarctica ?
Post by: sidd on April 09, 2018, 08:03:16 PM
The paper by Thomas et al. on antarctic snowfall is at

https://www.clim-past.net/13/1491/2017/cp-13-1491-2017.html

They find snowfall has been increasing since 1800. But there is a caveat at the end of the paper:

"However, the combined regional representation of these records is less than 30 % of the total Antarctic continent and includes single ice core sites with only limited regional representation in SMB. Our findings suggest that small changes in the high-accumulation AP, or the low-accumulation but geographically much larger EAP region, could change the sign and significance of the total Antarctic SMB trend dramatically."

Open access.

sidd
Title: Re: What's new in Antarctica ?
Post by: Shared Humanity on April 10, 2018, 02:29:19 AM
In other words, we're not sure.
Title: Re: What's new in Antarctica ?
Post by: sidd on April 20, 2018, 02:51:33 AM
The freshwater cap idea has been round for a while but here are observations and a (simple) model:
The idea is that more light meltwater enhances stratification and suppresses formation of dense saline shelf water. This allows warm circumpolar deep water to creep in and melt the ice faster.

https://phys.org/news/2018-04-reveals-antarctic-contributing-sea-climate.html

paper is

doi: 10.1126/sciadv.aap9467

open access. read all about it.

sidd
Title: Re: What's new in Antarctica ?
Post by: oren on April 21, 2018, 08:24:54 AM
The freshwater cap idea has been round for a while but here are observations and a (simple) model:
The idea is that more light meltwater enhances stratification and suppresses formation of dense saline shelf water. This allows warm circumpolar deep water to creep in and melt the ice faster.

https://phys.org/news/2018-04-reveals-antarctic-contributing-sea-climate.html

paper is

doi: 10.1126/sciadv.aap9467

open access. read all about it.

sidd
Thanks. Interesting paper, strongly grounded in observations.
Title: Re: What's new in Antarctica ?
Post by: bluesky on April 21, 2018, 11:03:19 PM
The freshwater cap idea has been round for a while but here are observations and a (simple) model:
The idea is that more light meltwater enhances stratification and suppresses formation of dense saline shelf water. This allows warm circumpolar deep water to creep in and melt the ice faster.

https://phys.org/news/2018-04-reveals-antarctic-contributing-sea-climate.html

paper is

doi: 10.1126/sciadv.aap9467

open access. read all about it.

sidd
Thanks. Interesting paper, strongly grounded in observations.

Here is the link to the full paper in Sciences Advances, for whatever reason the link on phys.org is out of order
http://advances.sciencemag.org/content/4/4/eaap9467.full

"On warm continental shelves, as those on the Sabrina Coast and in the Amundsen Sea, MCDW drives rapid ice shelf basal melt. The large volume of glacial meltwater prevents DSW (Dense Shelf Water)  formation in polynyas downstream of the meltwater outflow. MCDW (Modified Circumpolar Deep Water) remains in the bottom layer throughout the year in the polynya and further downstream, where it can access the ice shelf cavities. On cold continental shelves, the ice shelf cavities are filled by cold shelf waters, and basal melt rates are low. Glacial meltwater input is not sufficient to suppress winter convection in polynyas downstream of the meltwater outflow, as seen at Cape Darnley Polynya, allowing formation of DSW, the precursor to Antarctic Bottom Water. "


Further explanation on MCDW and Antarctica sea water circulation in EGU blog:
https://blogs.egu.eu/divisions/cr/tag/modified-circumpolar-deep-water/




Title: Re: What's new in Antarctica ?
Post by: ivica on May 12, 2018, 11:51:40 PM
http://m.esa.int/Our_Activities/Observing_the_Earth/CryoSat/New_view_of_Antarctica_in_3D

"Thanks to ESA’s CryoSat mission, a new map of Antarctica provides the most accurate 3D view ever of the continent’s vast ice sheet and floating ice shelves.

This latest digital elevation model, which is available for download (http://www.cpom.ucl.ac.uk/csopr/icesheets2/dems.html?ais_subject=dem&user_type=normal), is a result of research (https://www.the-cryosphere.net/12/1551/2018/) published recently in The Cryosphere. The model replaces the version published in March 2017."

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fm.esa.int%2Fvar%2Fesa%2Fstorage%2Fimages%2Fesa_multimedia%2Fimages%2F2018%2F05%2Fice_height%2F17505648-1-eng-GB%2FIce_height_article_mob.png&hash=ef59dc6e9ba8740c849bffee0786588a)
Ice height: Released 11/05/2018 2:30 pm, CPOM

"Using around 250 million measurements taken by ESA’s CryoSat mission between 2010 and 2016, scientists at the UK Centre for Polar Observation and Modelling have created the most comprehensive picture to date of the height of the Antarctic ice sheet. This is about five million more than were used in the 2017 version, giving a snapshot of the height of the ice across 95% of the continent."
Title: Re: What's new in Antarctica ?
Post by: Juan C. García on May 18, 2018, 02:30:28 AM
Someone, somewhere, is making a banned chemical that destroys the ozone layer, scientists suspect

https://www.washingtonpost.com/news/energy-environment/wp/2018/05/16/someone-somewhere-is-making-a-banned-chemical-that-destroys-the-ozone-layer-scientists-suspect/?utm_term=.456ef9ccc84a&wpisrc=nl_green&wpmm=1 (https://www.washingtonpost.com/news/energy-environment/wp/2018/05/16/someone-somewhere-is-making-a-banned-chemical-that-destroys-the-ozone-layer-scientists-suspect/?utm_term=.456ef9ccc84a&wpisrc=nl_green&wpmm=1)
Title: Re: What's new in Antarctica ?
Post by: lurkalot on May 24, 2018, 09:14:32 PM
Giant canyons found in trans-antarctic mountains:
http://www.bbc.co.uk/news/science-environment-44245893
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on May 29, 2018, 05:28:16 PM
Giant canyons found in trans-antarctic mountains:
http://www.bbc.co.uk/news/science-environment-44245893

Nice: (https://ichef.bbci.co.uk/news/624/cpsprodpb/1435F/production/_101738728_2f8ff45c-8ec8-4077-8634-c4c2b4857b20.jpg)
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on June 06, 2018, 04:44:56 AM
from Earth Observatory, 6 June 2018: https://earthobservatory.nasa.gov/IOTD/view.php?id=92238&src=eoa-iotd (https://earthobservatory.nasa.gov/IOTD/view.php?id=92238&src=eoa-iotd)
End of the Journey for Iceberg B-15Z?

(https://eoimages.gsfc.nasa.gov/images/imagerecords/92000/92238/b15z_location_map.png)

Quote
When astronauts aboard the International Space Station shot this photograph on May 22, 2018, B-15Z measured 10 nautical miles long and 5 nautical miles wide. That’s still well within the trackable size. But the iceberg may not be tracked much longer if it splinters into smaller pieces. A large fracture is visible along the center of the berg, and smaller pieces are splintering off from the edges.

(https://eoimages.gsfc.nasa.gov/images/imagerecords/92000/92238/iss055e074583.jpg)

[Note: The original presents more information in a different order.]
Title: Re: What's new in Antarctica ?
Post by: Yuha on June 07, 2018, 04:26:49 PM
from Earth Observatory, 6 June 2018: https://earthobservatory.nasa.gov/IOTD/view.php?id=92238&src=eoa-iotd (https://earthobservatory.nasa.gov/IOTD/view.php?id=92238&src=eoa-iotd)
End of the Journey for Iceberg B-15Z?

Still visible on worldview on June 4: https://go.nasa.gov/2JohX6Q (https://go.nasa.gov/2JohX6Q)
It has split along the fracture.

Next day it is barely visible through the clouds, but it is still high enough to cause ripples in the clouds.
Title: Re: What's new in Antarctica ?
Post by: Lennart van der Linde on June 13, 2018, 08:10:37 PM
Ice loss from Antarctica increased from circa 55 Gt/yr to circa 187 Gt/yr over past 25 years, according to:

Shepherd et al 2018, Mass balance of the Antarctic Ice Sheet from 1992 to 2017:
https://www.nature.com/articles/s41586-018-0179-y

Abstract
The Antarctic Ice Sheet is an important indicator of climate change and driver of sea-level rise. Here we combine satellite observations of its changing volume, flow and gravitational attraction with modelling of its surface mass balance to show that it lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017, which corresponds to an increase in mean sea level of 7.6 ± 3.9 millimetres (errors are one standard deviation). Over this period, ocean-driven melting has caused rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. We find large variations in and among model estimates of surface mass balance and glacial isostatic adjustment for East Antarctica, with its average rate of mass gain over the period 1992–2017 (5 ± 46 billion tonnes per year) being the least certain.
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on June 13, 2018, 08:17:00 PM
I see this is a report on the (recently posted) original material from Lennart van der Linde, but will put it in anyway.

Antarctic ice loss has tripled in a decade. If that continues we are in serious trouble.
https://www.washingtonpost.com/news/energy-environment/wp/2018/06/13/antarctic-ice-loss-has-tripled-in-a-decade-if-that-continues-we-are-in-serious-trouble/ (https://www.washingtonpost.com/news/energy-environment/wp/2018/06/13/antarctic-ice-loss-has-tripled-in-a-decade-if-that-continues-we-are-in-serious-trouble/)

From Chris Mooney at Washington Post, this is not a primary source.
Title: Re: What's new in Antarctica ?
Post by: sidd on June 13, 2018, 10:32:22 PM
I attach fig 2 and table 1 from the IMBIE paper. Comparing 1992-1997 to 2012-2017 shouw the mass loss rate tripling for WAIS and more than quadrupling for the peninsula.

That  issue of Nature has many good papers on Antarctica. It will take me a while to go thru them all.

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on June 16, 2018, 07:19:07 PM
As I mentioned, the latest issue of Nature has several papers on Antarctica. I have not fully absorbed any of them yet, since i have been running around the midwest, but here are my gleanings so far.

IMBIE paper doi: 10.1038/s41586-018-0179-y

I have already posted a figure and a table previously. Here are some more excerpts, and my comments.

1)They find strong increase in overall mass loss from WAIS and the peninsula.

"At the Antarctic Peninsula, the 25-year average rate of ice-sheet mass balance is −20 ± 15 Gt/yr, with an increase of about 15 Gt/yr in losses since 2000. The strongest signal and trend has occurred in West Antarctica, where rates of mass loss increased from 53 ± 29 Gt/yr to 159 ± 26 Gt/yr between the first and final five years of our survey; the largest increase occurred during the late 2000s when ice discharge from the Amundsen Sea sector accelerated [33] . Both of these regional losses are driven by reductions in the thickness and extent of floating ice shelves, which has triggered the retreat, acceleration and drawdown of marine-terminating glaciers [34] . The least certain result is in East Antarctica, where the average 25-year mass trend is 5 ± 46 Gt/yr . Overall, the AIS lost 2,720 ± 1,390 Gt of ice between 1992 and 2017, an average rate of 109 ± 56 Gt/yr."

2) Regarding SMB, they find that there is no trend across AIS: "The temporal variability of all products is similar and they all agree on the absence of an ice-sheet-wide trend in SMB over the period 1979–2017, which implies that recent mass loss from the AIS is dominated by increased solid-ice discharge into the ocean. "

"The temporal variability of all products is similar and they all agree on the absence of an ice-sheet-wide trend in SMB over the period 1979–2017, which implies that recent mass loss from the AIS is dominated by increased solid-ice discharge into the ocean."

3) GIA uncertainties are important, and particularly so in the critical sector of Amundsen:

"Models predict the greatest rates of solid-Earth uplift (5–7 mm/yr on average) in areas where GIA is a substantial component of the regional mass change, such as the Amundsen, Ross and Filchner–Ronne sectors of West Antarctica (see Extended Data Fig. 4), but also the greatest variability (for example, a standard deviation of more than 10 mm/yr in the Amundsen sector). Away from areas with large GIA signals there is low variance among the models and broad agreement with GPS observations [45] ."

sidd





Title: Re: What's new in Antarctica ?
Post by: sidd on June 16, 2018, 08:02:41 PM
Another paper in this issue of Nature is a review by Shepherd et al. doi: 10.1038/s41586-018-0171-6 of the satellite record across Antarctica.

Somewhat surprisingly, they state that the overall rate of ice loss has "changed little" since 1992. I suspect they have a different definition of substantial change than I do.

"these studies show that the continent has contributed 7.6 ± 3.9 mm to global sea levels since 1992. Two-fifths (3.0 ± 0.6 mm) of this loss occurred during the past five years 10 . Although the rate of ice loss from the entire Antarctic ice sheet has changed little during the satellite record, speedup of glacier flow in the Amundsen Sea sector has led to accelerated losses from this region [37,38] ."

They note the evicence for ocean forced dynamic thinning:

"Although most of Antarctica has remained stable over the past 25 years, there are clear patterns of imbalance in many coastal sectors—such as the thickening of the Kamb Ice Stream and the thinning of glaciers flowing into the Amundsen Sea and at the Antarctic Peninsula. These changes reflect imbalance between ice flow and snow accumulation within the surrounding catchments. The pace of ice flow at the Kamb Ice Stream is unusually low [40] and has not altered in recent decades, but analysis of ice-penetrating radar measurements [41] shows that it stagnated over a century ago. Elsewhere, inland glacier thinning is almost exclusively coincident with contemporaneous ice speedup [21,42,43] (indicating that the thinning is dynamic in nature) and with perturbations at the marine termini of the glaciers [44] (indicating that the thinning has resulted from ocean forcing)."

On subglacial lakes:

"However, localized and episodic rises and falls of the ice sheet surface were then spotted in satellite interferometric [46] and altimetric records [47,48] , suggesting otherwise. These fluctuations, amounting to changes in height of 1–10 m over sub-decadal timescales, are interpreted to be the surface expressions of water transferring between active subglacial lake networks. More than a hundred active lakes have now been identified using this approach [49] ... Thanks to these data, we now know that in addition to periodically flushing subglacial cavities, the presence [52] of and fluctuations [27] in subglacial lake water can lubricate ice flow in parts of the continent."

Ice shelves: They note the majors (Ross, Ronne, Amery) are stable since the 1990s

"Although the major Ross, Filchner-Ronne, and Amery ice shelves have remained stable since the 1990s,"

That is something of a relief, I worry about Amery. (Not that i dont worry about the other two ...)

They continue:

"many ice shelves in West Antarctica have experienced long-term thinning over the same period. In the locations where retreat or thinning have occurred, the grounded ice inland has also been destabilized. The dominant control on this pattern is believed to be the presence (or absence) of warm ocean currents offshore [59] . Altogether, the volume of Antarctic ice shelves has declined through net overall thinning (166 ± 48 km^3/yr between 1994 and 2012; ref. 11 ) and through progressive calving-front retreat of those at the Antarctic Peninsula (210 ± 27 km^3/yr between 1994 and 2008; ref. 3 ). Combined, these losses amount to less than 1% of their volume. However, the highest ice shelf thinning rates have occurred in the Amundsen and Bellingshausen seas [12] , where five have lost between 10% and 18% of their thickness [11] owing to ocean-driven melting at their bases [67] ."

They briefly discuss the Larsen collapses also nd point out that thinning may not be a prerequisite for collapse:

" The relationship is, however, not universal; for example, although the Wilkins ice shelf collapsed in 2009, it did not thin in the preceding five years [79] ."

Wilkins was one of Mercer's canaries.

They discuss the speedup in glacier flows after shelves disappear leading to dynamic thinning:

"Over the past two decades, for example, surface lowering has spread inland across the drainage basins of the Pine Island and Thwaites glaciers at speeds of between 5 and 15 km/yr, and the majority of their catchments are now in a state of dynamical imbalance (they are thinning owing to accelerated flow)."

They point out reasons that the Amundsen region is vulnerable:

"Glaciers flowing into the Amundsen Sea sector of West Antarctica are particularly susceptible to climate forcing, owing to their geometrical configuration and the absence of any substantial ice shelf barrier [90] , and today the pace of ice sheet retreat along parts of this coastline dwarfs that during the Holocene period. The region’s ice shelves have thinned [11,12] by 3 to 6 m/yr, and its glacier grounding lines have retreated [85,86] by 10 to 35 km since 1992, which is 20 to 30 times the rate since the Last Glacial Maximum ..."

Ocean forcing is clearly implicated:

"The forcing for these events is now widely regarded to lie in the surrounding ocean, because ice drawdown has originated at and evolved from the terminus of neighbouring but distinct ice flow units [42], and because warm [67] and warming [44] water is present within the cavities beneath their peripheral ice shelves."

But the situation is complicated. Although

"it has been concluded [94] that the region is now undergoing marine ice sheet instability, with no geometrical obstacles to prevent irreversible decline."

there other clues that the process is not so straightforward, and doom might take it's own sweet time:

"However, satellite observations have revealed that retreat of the Pine Island Glacier halted around 2011 [95,96],and that ice thinning inland abated in the following years [88]. This suggests that the situation is more complicated than a consideration of the glacier geometry alone, and may involve changes in the degree of ocean forcing, as has occurred in the recent past [87,97] ."

Thy have an extended discussion of sea ice which i will not cover here.

In the summary:

"Although persistent ice shelves have fringed Antarctica for thousands of years 56 , there is now widespread evidence of changes in their extent [14]] and thickness [3,11] . Altogether, their volume has decreased by more than 300 km^3/yr since 1994 [3,11] , notably due to collapse and calving at the Antarctic Peninsula and rapid thinning of those in the Amundsen and Bellingshausen seas. These events have triggered retreat [85,86] and acceleration [21,43] of marine-terminating glaciers and ice streams around the continent, leading to the drawdown of ice from their inland catchments [39,42] . Since 1992, the grounded ice sheet has lost 1,350 ± 1,010 Gt of ice, causing a net 3.8 ± 2.8 mm contribution to global sea level rise [36] ."

The question remains:

"A key unanswered science question is how long it will take for the ice shelves that are currently thinning to reach a point whereby they are no longer providing effective buttressing for the grounded ice inland."

Indeed. Inquiring minds want to know, and every coastal community in the world needs to know.

I attach figs 1 and 2. They are very pretty.

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on June 16, 2018, 08:30:56 PM
In some happier news, a letter by Shakun et al. doi: 10.1038/s41586-018-0155-6 finds that land based EAIS was stable over the last 8 Myr:

"These findings indicate that atmospheric warming during the past eight million years was insufficient to cause widespread or long-lasting meltback of the EAIS margin onto land.We suggest that variations in Antarctic ice volume in response to the range of global temperatures experienced over this period—up to 2–3 degrees Celsius above preindustrial temperatures [4] , corresponding to future scenarios involving carbon dioxide concentrations of between 400 and 500 parts per million—were instead driven mostly by the retreat of marine ice margins, in agreement with the latest models [5,6] ."

They base their conclusion on the lack of cosmogenic isotopes from ANDRILL and modelling:

"The near absence of cosmogenic nuclides in our record therefore rules out substantial and long-lasting EAIS retreat onto land during the past 8 Myr ..."

"these models suggest that warming consistent with even the most intense interglacials of the past 8 Myr would have produced minimal land exposure around the entire EAIS margin [6,8] ."

"our findings agree with model simulations which show that the terrestrial EAIS experiences minimal melt when carbon dioxide levels are at their present value of roughly 400 parts per million for extended periods of time, whereas some marine-based ice-sheet sectors largely disappear [5,23]"

ANDRILL is a gift that keeps on giving.

There are, of course, large basins of EAIS (Totten comes to mind) where ice is grounded well below present day sea level. More drilling clearly needed.

I note there are some heavy hitters on that author list. Naish must have done a lot of the modelling.

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on June 16, 2018, 08:53:12 PM
Another letter in this issue of Nature is from Kingslake et al. doi: 10.1038/s41586-018-0208-x who see retreat and re-advance of WAIS during the last deglaciation. They analyse cores from the seafloor, ice  penetrating radar scans and models :

"Rebound-driven stabilizing processes were apparently able to halt and reverse climate-initiated ice loss. Whether these processes can reverse present-day ice loss [6] on millennial timescales will depend on bedrock topography and mantle viscosity—parameters that are difficult to measure and to incorporate into ice-sheet models."

So WAIS retreated, but then isostatic rebound elevated the previously ice covered regions sufficiently to allow the sheet to re-advance. Note that this uplift occurs over millennial timescales, so may not be important for, say, the next thousand years.

Their reconstruction (using PISM) shows that Ross and Ronne almost completely disappeared around 10KYr ago, and then the grounding lines re-advanced to present day.

"In this simulation, rising sea-level and surface temperatures during the last glacial termination drive grounding-line retreat through regions currently occupied by the Ronne and Ross ice shelves. The grounding line reaches its most retreated position around 10 thousand years (kyr) before present (bp), up to approximately  300 km inland of the present-day grounding line (Fig. 3 and Extended Data Fig. 3). Retreat exposes nearly all of our core sites and the bed of HIR to the ocean. Approximately 352,000 km 2 of the area that is covered by grounded ice today ungrounds during retreat, resulting in lithospheric rebound of up to 175 mm per year. The rising bed eventually causes the Ross and Ronne ice shelves to ground on bathymetric highs in the locations of present-day ice rises, including HIR. Ice-rise formation increases ice-shelf buttressing, causing the grounding line to re-advance towards its present-day location (Fig. 3 and Extended Data Fig. 4; Methods) "

But not so for Amundsen: "In the Amundsen Sea sector, the grounding line retreats to its modern position without substantial inland retreat and re-advance. "

The go out on a limb, i think, with this speculation:

"Furthermore, we hypothesize that the grounding line in the Weddell and Ross Sea sectors may be capable of retreating far inland of its present position without triggering runaway ice-sheet collapse."

But they do note the troubles with Amundsen:

"We note that our model does not simulate retreat and rebound driven re-advance in the Amundsen Sea sector (Fig. 3), where present-day retreat of the grounding line is causing concern about future runaway collapse 6 and recent re-advance could explain observed sub-shelf iceberg ploughmarks [28] . Our findings motivate future work to examine whether rebound-driven mechanisms could slow or reverse this retreat on millennial timescales."

I attach figure 3. They have a movie also, but i had difficulty with it, seemed to have random black patches.

sidd







Title: Re: What's new in Antarctica ?
Post by: sidd on June 16, 2018, 09:04:43 PM
Rintoul has a perspective and a review in this issue of Nature. The Perspective lays out an optimistic and a pessimistic scenario for AIS upto 2070. These depend on human behaviour over the next fifty years, so should be taken as an informed guess.

"Under the high-emissions scenario, Antarctica and the Southern Ocean undergo widespread and rapid change, with global consequences. But the environmental change realized by 2070 will be only a fraction of the change to which we are committed by choices made today, and the rate of change will have increased and continue to accelerate. For example, once initiated, the marine ice sheet instability will result in irreversible loss of large parts of the ice sheet resting on bedrock below sea level. Under the low-emissions scenario, in which global average temperatures remain within 2 °C of 1850 values, there is some chance that the buttressing ice shelves will survive and the Antarctic contribution to sea level rise will remain below 1 m. Under the high-emissions scenario, the ice shelves are lost and Antarctica contributes 0.6 m to 3 m of sea level rise by 2300, with an irreversible commitment [45] of 5 m to 9 m, or as much as [33] 15 m in the coming millennia."

But even in the optimistic scenario, the qualifier "there is some chance" seems to show his doubts.

The review is a magisterial analysis of local and extended dynamics of the Southern ocean.. I shall not attempt a detailed reading here, except to quote Rintoul on the uncertainties:

"The theoretical foundation for Southern Ocean dynamics is developing rapidly, but remains incomplete. This gap is reflected, for example, by the speculative nature of the above discussion of the response of the Southern Ocean to changes in forcing and by our inability to do much more than list the mechanisms that influence the delivery of ocean heat to the Antarctic margin. The fact that new observations continue to reveal surprises that challenge existing thinking also underscores gaps in knowledge; examples include the unanticipated variability of the Southern Ocean carbon sink, the dominant contribution of the Southern Hemisphere to the change in global ocean heat content in the past decade, and evidence that the East Antarctic Ice Sheet is more exposed to ocean heat transport than once thought."

Don't get me wrong. This review is required reading for an understanding of Southern ocean dynamics.

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on June 16, 2018, 09:37:56 PM
Two other papers came to my attention, althoug not from Nature:

Bamber et al. doi: 10.1088/1748-9326/aac2f0 look at land ice contribution to sea level rise in the satellite era. Their result is smaller than many GRACE derivations, which they claim is due to smaller trends for glaciers and ice caps.

Dow et al. doi: 10.1126/sciadv.aao7212 analyse the effect of basal channelized melt on ice shelf fracture. Their principal area is Nansen but they have this to say about PIG:

"Pine Island Glacier is one of the most vulnerable regions of the Antarctic to ice shelf collapse and has seen marked thinning rates and grounding line retreat over the last decade (4, 6). Pine Island Glacier Ice Shelf has had five large calving events between 2000 and 2017. The fracture that grew to cause the most recent calving event in September 2017 initiated over one of the ice shelf basal channels. The channels have been identified from MODIS imagery (5) and radar surveys (6). A 4-km-wide polynya identified from Landsat imagery in 2000 also supports the presence of a channel in this location. The fracture (Fig. 1G) can first be seen in March 2015 with a length of 3.7 km. By February, the fracture had moved 3.4 km downstream and lengthened to 7 km. In January 2017, the fracture was 5.4 km downstream and 19 km long. This fracture culminated in a calving event in September 2017 creating the 185-km 2 B-44 iceberg. The formation of a fracture originating from the center of the ice shelf and propagating laterally, rather than from the edge toward the center has previously been attributed to crevasses originating from the grounding line (27). Here, we suggest that thinning within the basal channel is a driver for the initial transverse location of the fracture, and the role of grounding line originated crevasses is to determine the longitudinal location of fracture formation."

I attach the picture for PIG, but they have many others including Totten and Petermann.

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on June 17, 2018, 12:29:32 AM
I seem to have omitted the Massom paper doi:10.1038/s41586-018-0212-1 on the protective effect of sea ice on ice shelves through attenuation of ocean swell. They intensively examine the Larsen and Wilkins collapses.

"A decadal-scale reduction of sea ice coverage (concentration, that is the proportion of the ocean surface covered by sea ice, and duration) over the satellite era (since 1979) in the northwestern Weddell Sea and the Bellingshausen Sea (Fig. 3; also ref. 27 ) dramatically increased the potential for substantial ocean wave energy to reach the ice shelf fronts in mid- to late summer and in early autumn. An increase in
open-water duration of approximately three months occurred between 1979/1980 and 2009/2010 [27]."

"The sea ice loss in each case resulted in extensive and sustained periods of exposure to broadly open-ocean conditions offshore "

"Occurring immediately before each disintegration event, sliver-berg calvings (Fig. 2) removed keystone blocks from the arch-like configuration of the ice shelf front that were crucial to its structural integrity."

i attach figure 3, showing decline in sea ice in the region.

sidd


Title: Re: What's new in Antarctica ?
Post by: oren on June 17, 2018, 12:48:55 AM
Thank you Sidd for all these summaries.
Title: Re: What's new in Antarctica ?
Post by: sidd on June 17, 2018, 01:32:30 AM
I'm afraid they dont deserve to be called summaries. Consider them no more than my immediate reactions. It will take me weeks to read through them with the care they warrant.

I suggest reading at least the abstracts  for a precis of the most important results. I know I skipped a lot.

sidd
Title: Re: What's new in Antarctica ?
Post by: litesong on June 17, 2018, 09:52:18 PM
[quote author=Lennart van der Linde link=topic=622.msg158630#msg158630  Ice loss from Antarctica increased from circa 55 Gt/yr to circa 187 Gt/yr over past 25 years, according to:
Shepherd et al 2018, Mass balance of the Antarctic Ice Sheet from 1992 to 2017:
https://www.nature.com/articles/s41586-018-0179-y
Abstract
The Antarctic Ice Sheet ......lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017..... rates of ice loss from West Antarctica to increase from 53 ± 29 billion to 159 ± 26 billion tonnes per year; ice-shelf collapse has increased the rate of ice loss from the Antarctic Peninsula from 7 ± 13 billion to 33 ± 16 billion tonnes per year. [/quote]

Meanwhile, Grace FO continues its shake down, now in a preliminary orbit:
https://www.jpl.nasa.gov/news/news.php?feature=7156
From the article:
The GRACE-FO microwave ranging instruments allow distance measurements with a precision better than one micron -- less than the diameter of a blood cell, or a tenth the width of a human hair....... To demonstrate the initial performance of GRACE-FO's microwave ranging system, the team examined its measurements of changes in the distance between the two satellites as they flew over the Himalayas...... The plot's wavy lines show how the distance between the satellites varies as the satellites pass over oceans, land areas, and particularly mountains as they orbit Earth. The observed inter-satellite distance changes, which can be as large as hundreds of microns, are in good agreement with expectations. These results give the team confidence that the mission's key microwave ranging system is performing well.
By measuring even minute changes in distance between the satellites, GRACE-FO can detect the month-to-month variations in Earth's gravity field caused by the movement of mass as small as about a half-inch (1 centimeter) of water over an area of about 200 miles (320 kilometers) in diameter.
///////
Good news, indeed!
Title: Re: What's new in Antarctica ?
Post by: Sleepy on June 18, 2018, 05:06:58 AM
I'm afraid they dont deserve to be called summaries. Consider them no more than my immediate reactions. It will take me weeks to read through them with the care they warrant.

I suggest reading at least the abstracts  for a precis of the most important results. I know I skipped a lot.

sidd
Thanks for your posts.
FWIW, I noticed LVDL's post on the 13th and even posted a short comment here:
https://forum.arctic-sea-ice.net/index.php/topic,428.msg158958.html#msg158958 (https://forum.arctic-sea-ice.net/index.php/topic,428.msg158958.html#msg158958)
Also saw Susan's post but none of yours, despite visiting the forum every single day.

In the past one always had the mail notifications, now one must login every single time or you loose the notifications. I don't like that, since there are some threads that I rarely comment in but do try to follow, like this one.

Why did Neven change this setting?
Title: Re: What's new in Antarctica ?
Post by: sidd on June 18, 2018, 05:32:52 AM
There is a link called "Show unread posts since last visit."  that shows all the threads with unseen posts.

sidd
Title: Re: What's new in Antarctica ?
Post by: Sleepy on June 18, 2018, 05:42:33 AM
Thanks, I've already worn out my scroll-wheel once. ;)
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on June 18, 2018, 05:42:24 PM
Sidd, that is some outstanding review, I'm looking forward to taking a closer look when there is time. Please don't forget that I am an amateur amateur, and normally if I have something to say about ice, it is because of somebody else's work.
Title: Re: What's new in Antarctica ?
Post by: sidd on June 19, 2018, 07:17:46 AM
More bad news. Cook in East Antarctica is more unstable than previously known:

doi: 10.5194/tc-2018-107

"We have shown that despite little change over the past decade, there have been dynamic
changes in the velocity of both the Cook East and West glaciers during periods over the past
~45 years. For Cook East we provide one of the few observations linking a short-lived increase
in velocity to a subglacial flood event, in addition to a longer-term velocity increase of 19%
between 1989 and 2001. For Cook West we link a doubling of its velocity to the near-complete
loss of its floating ice shelf between 1973 and 1989, which may have been forced by a more
variable climate in the mid-20th century"

Open access. Read all about it.

I attach fig 7

sidd
Title: Re: What's new in Antarctica ?
Post by: sidd on June 21, 2018, 10:10:33 PM
Some good news from Antarctica: I post extracts here:

https://forum.arctic-sea-ice.net/index.php/topic,2205.msg159984/topicseen.html#msg159984

In light of this result, I suspect Kinslake et al. (on which i commented earlier) may visit to recalculate their results in the Amundsen secto, since the crust beneath is more labile than they assumed. This may help make their results in that area better.

sidd
Title: Re: What's new in Antarctica ?
Post by: litesong on July 06, 2018, 05:01:40 PM
Meanwhile, Grace FO continues its shake down, now in a preliminary orbit:
https://www.jpl.nasa.gov/news/news.php?feature=7156
From the article:
To demonstrate the initial performance of GRACE-FO's microwave ranging system, the team examined its measurements of changes in the distance between the two satellites as they flew over the Himalayas...... GRACE-FO can detect the month-to-month variations in Earth's gravity field caused by the movement of mass as small as about a half-inch (1 centimeter) of water over an area of about 200 miles (320 kilometers) in diameter.
Grace-FO continues to prepare itself for accurate measurements of Earth gravity changes:
https://gracefo.jpl.nasa.gov/news/138/first-laser-light-for-grace-follow-on/
From the article:
 The LRI, which is being flown as a technology demonstration, has made its first measurements in parallel with GRACE-FO's main microwave ranging instrument, and initial comparisons of the data from the two types of instruments show that they agree as expected.
///////
Further Grace-FO alignments appear to continue the good news for Grace-FO.
Title: Re: What's new in Antarctica ?
Post by: Lennart van der Linde on July 16, 2018, 11:51:51 PM
Pattyn 2018 on The paradigm shift in Antarctic ice sheet modelling:
https://www.nature.com/articles/s41467-018-05003-z

And some more on ice sheets:
https://www.nature.com/collections/vqrdvgyjdp
Title: Re: What's new in Antarctica ?
Post by: sidd on July 17, 2018, 06:33:51 AM
Thanx for the pointers. Nice articles.

sidd
Title: Re: What's new in Antarctica ?
Post by: kassy on July 17, 2018, 02:12:41 PM
Kelp and sadly also plastics can make it to Antarctica if storms help them across the ACC:

Antarctica is surrounded by the circumpolar current, an endless loop of water pushing ever-eastward, driven by the powerful southern winds and unobstructed by land, other than being forced through the narrow gap between the Antarctic Peninsula and Tierra del Fuego. Although whales and seabirds can power across this obstacle, few other life forms can do so, keeping the frozen continent almost biologically isolated from the rest of the planet.

At least that is what was believed, until the Universidad de Concepción's Dr Erasmo Macaya, unable to do the work he had come to King George Island to do, spent a lot of time walking along the beaches looking at seaweed. Macaya noticed that some of the kelp didn't look like it should be there. The oceans off Antarctica, cold as they are, do support some kelp species, but Macaya's finds were Durvillaea antarctica, which somewhat ironically does not normally live close to the continent with which it shares its name.

More details on:

http://www.iflscience.com/environment/kelp-is-undertaking-epic-voyages-to-reach-antarctica-and-we-finally-know-how/
Title: Re: What's new in Antarctica ?
Post by: litesong on July 25, 2018, 02:52:05 AM
I've already worn out my scroll-wheel once.
Tesla Model 3 has two scroll-wheels......ha ha
Title: Re: What's new in Antarctica ?
Post by: Susan Anderson on July 27, 2018, 11:50:46 PM
Interesting circulation, and I'd guess it's a bit warm for the season:
https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=302.24,-91.35,442 (https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=302.24,-91.35,442)
Title: Re: What's new in Antarctica ?
Post by: bluesky on August 15, 2018, 04:41:56 PM
Not sure this paper has been linked somewhere in ASIF, apologies if it is the case, no free article for the moment:

West Antarctic Ice Sheet retreat in the Amundsen Sea driven by decadal oceanic variability
Adrian Jenkins et al, Nature Geoscience

https://www.nature.com/articles/s41561-018-0207-4

Abstract:
"Mass loss from the Amundsen Sea sector of the West Antarctic Ice Sheet has increased in recent decades, suggestive of sustained ocean forcing or an ongoing, possibly unstable, response to a past climate anomaly. Lengthening satellite records appear to be incompatible with either process, however, revealing both periodic hiatuses in acceleration and intermittent episodes of thinning. Here we use ocean temperature, salinity, dissolved-oxygen and current measurements taken from 2000 to 2016 near the Dotson Ice Shelf to determine temporal changes in net basal melting. A decadal cycle dominates the ocean record, with melt changing by a factor of about four between cool and warm extremes via a nonlinear relationship with ocean temperature. A warm phase that peaked around 2009 coincided with ice-shelf thinning and retreat of the grounding line, which re-advanced during a post-2011 cool phase. These observations demonstrate how discontinuous ice retreat is linked with ocean variability, and that the strength and timing of decadal extremes is more influential than changes in the longer-term mean state. The nonlinear response of melting to temperature change heightens the sensitivity of Amundsen Sea ice shelves to such variability, possibly explaining the vulnerability of the ice sheet in that sector, where subsurface ocean temperatures are relatively high."

not much on BAS
https://www.bas.ac.uk/media-post/melt-rate-of-west-antarctic-ice-sheet-highly-sensitive-to-changes-in-ocean-temperatures/
Title: Re: What's new in Antarctica ?
Post by: Niall Dollard on August 28, 2018, 12:13:30 PM
It got down to -82.4 C at Vostok yesterday.

(Record low there is -89.2 on 21/7/1983).
Title: Re: What's new in Antarctica ?
Post by: sidd on September 05, 2018, 08:49:19 PM
New surface elevation map from University of Minnesota and Ohio State

https://www.pgc.umn.edu/data/rema/

sidd
Title: Re: What's new in Antarctica ?
Post by: Tony Mcleod on September 11, 2018, 07:33:32 AM
Not sure where to ask this but...
Is there a link to a Wipneus Antarctic only graph?
Like this link is for global https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_global_area_byyear_b.png (https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_global_area_byyear_b.png).
Title: Re: What's new in Antarctica ?
Post by: oren on September 11, 2018, 10:51:50 AM
Not sure where to ask this but...
Is there a link to a Wipneus Antarctic only graph?
Like this link is for global https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_global_area_byyear_b.png (https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_global_area_byyear_b.png).
Checking https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf (https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf) I can see a link to such a graph https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_antarctic_area_byyear.png?attredirects=0 (https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/grf/nsidc_antarctic_area_byyear.png?attredirects=0), however the graph is not up to date. PM Wipneus and he will probably be able to fix it easily or provide you with an alternate link.
Title: Re: What's new in Antarctica ?
Post by: Neven on September 20, 2018, 07:46:05 PM
This may have been posted elsewhere, but as a geoengineering scheme, this looks pretty interesting on the face of it. The Guardian:

Quote
Build walls on seafloor to stop glaciers melting, scientists say (https://www.theguardian.com/environment/2018/sep/20/build-walls-on-seafloor-to-stop-glaciers-melting-scientists-say)

Building walls on the seafloor may become the next frontier of climate science, as engineers seek novel ways to hold back the sea level rises predicted to result from global warming.

By erecting barriers of rock and sand, researchers believe they could halt the slide of undersea glaciers as they disintegrate into the deep. It would be a drastic endeavour but could buy some time if climate change takes hold, according to a new paper published on Thursday in the Cryosphere journal, from the European Geosciences Union.

Though the notion may sound far-fetched, the design would be relatively straightforward. “We are imagining very simple structures, simply piles of gravel or sand on the ocean floor,” said Michael Wolovick, a researcher at the department of geosciences at Princeton University in the US who described the plans as “within the order of magnitude of plausible human achievements”.

The structures would not just be aimed at holding back the melting glaciers, but at preventing warmer water from reaching the bases of the glaciers under the sea. New research is now being undertaken by scientists showing how the effects of the warmer water around the world, as the oceans warm, may be the leading cause of underwater melting of the glaciers.
Title: Re: What's new in Antarctica ?
Post by: gerontocrat on September 20, 2018, 08:27:42 PM
This may have been posted elsewhere, but as a geoengineering scheme, this looks pretty interesting on the face of it. The Guardian:

Quote
Build walls on seafloor to stop glaciers melting, scientists say (https://www.theguardian.com/environment/2018/sep/20/build-walls-on-seafloor-to-stop-glaciers-melting-scientists-say)

Building walls on the seafloor may become the next frontier of climate science, as engineers seek novel ways to hold back the sea level rises predicted to result from global warming.

The Kraken Wakes
Author: John Wyndham, published July 1953

The novel describes escalating phases of what appears to be an invasion of Earth by aliens.
The aliens are speculated to come from a gas giant, and thus can only survive under conditions of extreme pressures in which humans would be instantly crushed. The deepest parts of the oceans are the only parts of Earth in any way useful to them.

Humanity nevertheless feels threatened by this new phenomenon – particularly since the newcomers show signs of intensive work to adapt the ocean deeps to their needs.

In the final phase,the aliens begin melting the polar ice caps, causing sea levels to rise.
London and other ports are flooded, causing widespread social and political collapse. Eventually organised social and political life in general ceases to exist.

Ultimately, scientists in Japan develop an underwater ultrasonic weapon that kills the aliens. However, the global population has been reduced to between a fifth and an eighth of its pre-invasion level, and the world's climate has been changed permanently.

The book describes in some detail the ever greater efforts by society to prevent catastrophe rather than adapt to it. Higher and higher sea walls and other massive infrastructure - all doomed to fail.

To me it was a good illustration of the mind-set that says "we can fix it, no matter what it is". Man as the master of nature. I doubt if I will be around long enough to see sea walls in the Antarctic happen, though I am sure to see a lot of the built environment in Florida being put on stilts and an awful lot of new sea walls, raised roads etc. built on land.
___________________________________________________
And a cross post from Sidd


Quote
" We abuse and exploit Earth for the same reason we abuse and exploit one another: because we have lost a sense of kinship with our fellow human beings, with other species, and with our planetary home."

https://orionmagazine.org/article/conscience-and-resistance/

sidd
https://forum.arctic-sea-ice.net/index.php/topic,1130.msg173542.html#msg173542
Title: Re: What's new in Antarctica ?
Post by: oren on September 20, 2018, 11:09:54 PM
It is really so stupid. I am sure these scientists are well-meaning, and experts in their field, but what is more cost-effective: build hundreds or thousands of kilometers of underwater seawalls in the most inhospitable environment on Earth as a stopgap solution to a part of the problem, or deploy enough solar panels and wind turbines to stop climate change? I am sure the latter gives more bang for the buck, should some government or a global entity decide to actually do something.
Title: Re: What's new in Antarctica ?
Post by: Neven on September 21, 2018, 11:22:56 AM
I agree, but it's much better than seeding the atmosphere or oceans with chemicals. But only, as you say, if it turns out that things can't be stopped with renewable energy any longer, and time needs to be bought.
Title: Re: What's new in Antarctica ?
Post by: magnamentis on September 21, 2018, 11:45:10 PM
It is really so stupid. I am sure these scientists are well-meaning, and experts in their field, but what is more cost-effective: build hundreds or thousands of kilometers of underwater seawalls in the most inhospitable environment on Earth as a stopgap solution to a part of the problem, or deploy enough solar panels and wind turbines to stop climate change? I am sure the latter gives more bang for the buck, should some government or a global entity decide to actually do something.

sarcasm:

but if they build walls a few already filthy rich global players like haliburton can
further increase their wealth and power base while the solar panel and wind turbine
solution would let many participate and distribute the benefits among the entire
population, and THAT CANNOT BE ALLOWED you certainly can see ;)

now you know why i wrote sarc first, that saved many a few extra heart beats.

however i'm glad you wrote that, it was "about" what i thought but was sure that someone
willl find better words like so often.

nice week end @all


Title: Re: What's new in Antarctica ?
Post by: Sleepy on September 22, 2018, 07:31:05 AM
Very anthropogenic, that study was up here in mid March.
Jakobshavn would need a berm 5 km across and 100 metres high, which would be an enormous, but still feasible undertaking. But PIG is big daddy and his mother Thwaites, are in frickin' Antarctica...

https://www.csc.fi/-/tutkijat-ehdottavat-napajaatikoiden-sulamisen-hidastamista-geotekniikan-avulla (https://www.csc.fi/-/tutkijat-ehdottavat-napajaatikoiden-sulamisen-hidastamista-geotekniikan-avulla)

When stuff like this keeps popping up again and again, it just tells me that most people out there are still looking for a quick fixes and simple solutions. Apart from PV and Wind, number one on the list should be consume less but We don't want that. We still believe that We can maintain growth on a finite planet and news like these doesn't seem to matter much:
https://bios.fi/bios-governance_of_economic_transition.pdf (https://bios.fi/bios-governance_of_economic_transition.pdf)
https://www.sciencealert.com/un-draft-report-says-we-must-transition-economy-to-tackle-climate-change (https://www.sciencealert.com/un-draft-report-says-we-must-transition-economy-to-tackle-climate-change)
Title: Re: What's new in Antarctica ?
Post by: sidd on September 25, 2018, 10:53:15 PM
Nice paper on ice retreat in the eastern Ross shelf during last deglaciation. Apparently it took centuries for grounding line retreat after ice shelf collapse:

"the grounding-line position persisted for a minimum of 200 years and a maximum of 1400 years after ice shelf breakup."

The delay was due to the formation of a grounding zone wedge (GZW) of sediment. WDB refers to the study area, the Whales Deep Basin.

"In the case of the WDB, a centuries-long lag necessitates sediment aggradation from a high sediment flux. Sediment flux to the grounding line depends on several factors including the ice-sheet drainage area [Ref. 42] as well as the substrate erodibility and the presence/absence of melt water [Refs. 43,44] . In the case of the WDB, easily erodible unconsolidated Plio-Pleistocene strata underlie the WDB 45 and hence the paleo-BIS sediment flux was sufficiently high to deposit an unusually large-volume compound GZW [Ref. 41] that helped maintain a relatively stationary grounding line."

In the last sentences they warn that we may not have as much time:

"As concerns the potential for future ice-shelf collapse in the present-day interglacial, it is worth noting that many ice-stream systems are now grounded on the foredeepened inner continental shelves that is presumably underlain by either basement rock or other less erodible substrate. Hence, a transition to unbuttressed flow of those modern ice streams might be less able to maintain a grounding position by accelerated deposition of sediment within the grounding zone."

Open access, read all about it:

doi: 10.1038/s41598-018-29911-8

coverage at:

https://phys.org/news/2018-09-retracing-antarctica-glacial.html

sidd
Title: Re: What's new in Antarctica ?
Post by: Sebastian Jones on September 26, 2018, 06:00:23 PM
Anecdotal evidence of increased storminess in the Southern Ocean from amateur sailors who suffer very real consequences. The linked article is concerned with the very real effects on sailors racing or cruising this ocean.
"Average surface wind speeds and wave heights in the Southern Ocean have steadily increased since the 1960s and particularly so in the last 20 years. Significantly, the biggest spikes are seen in extreme peak conditions, and the “hottest” spot in the course is the stretch between Cape Town and Australia."
https://www.sailmagazine.com/racing/the-50th-anniversary-of-the-golden-globe (https://www.sailmagazine.com/racing/the-50th-anniversary-of-the-golden-globe)
Title: Re: What's new in Antarctica ?
Post by: sidd on September 28, 2018, 12:58:19 AM
This paper came out in July, but i seem to have missed it. Mohajerani et al. (the other authors are heavyweights, Velicogna and Rignot) tighten limits on Totten ice loss using GRACE data. Upshot it 18.5 +/- 6.6 Gtonne/yr from 2002-2016.

doi: 10.1029/2018GL078173

I attach fig 2.

sidd
Title: Re: What's new in Antarctica ?
Post by: gerontocrat on September 29, 2018, 12:31:40 PM
Moss Beds in East Antarctica not doing well. I did not know that they existed.

Climate change kills Antarctica's ancient moss beds

Quote
Emerging from the ice for a brief growing season every Antarctic summer, the lush green mosses of East Antarctica are finally succumbing to climate change. That is according to a study of the small, ancient and hardy plants - carried out over more than a decade. This revealed that vegetation in East Antarctica is changing rapidly in response to a drying climate.

The findings are published in the journal Nature Climate Change.

"Visiting Antarctica, you expect to see icy, white landscapes," said lead scientist Prof Sharon Robinson from the University of Wollongong, in Australia. "But in some areas there are lush, green moss beds that emerge from under the snow for a growing period of maybe six weeks."

While West Antarctica and the Antarctic Peninsula are some of the fastest warming places of the planet, East Antarctica has not yet experienced much climate warming, so the scientists did not expect to see much change in the vegetation there.

"But we were really surprised when we saw how fast it was changing," Prof Robinson said. "After a pilot study in 2000, we set up monitoring in 2003. When we returned in 2008, all these green moss beds had turned dark red, indicating they were severely stressed. It was a dramatic change. "They change from green to red to grey if they get really stressed. "The red pigments are the sunscreen and drought stress protective pigments they produce to protect themselves - antioxidant and UV screening compounds. "Grey means they are dying."
https://www.bbc.co.uk/news/science-environment-45629395
Title: Re: What's new in Antarctica ?
Post by: kassy on October 11, 2018, 04:45:46 PM
Rapid, widespread changes may be coming to Antarctica's Dry Valleys

...

Led by Andrew Fountain, a geology professor in PSU's College of Liberal Arts and Sciences, a team of researchers used an airborne laser scanner, or lidar, to measure the surface elevations of glaciers, soils and ice-covered lakes in Antarctica's largest exposed land region. The team then compared the elevations to similar measurements made in 2001 by a different project.
The work was support by the National Science Foundation, which manages the U.S. Antarctic Program, the nation's research endeavor on the southernmost continent.
The findings were reported Sept. 13 in the journal Geomorphology.

"Millions of cubic meters of buried ice have melted in the last decade," said Joseph Levy, the paper's lead author and an assistant professor of geology at Colgate University. "It's unprecedented change over the historic period of Antarctica and perhaps since the end of the last ice age. If it keeps up, it could remove the last ice deposits from some valleys in about five hundred years."

Levy said they believe the culprit is meltwater. When soils thaw and become wet from melting the buried ice below, their insulating capacity is reduced and they conduct much more heat.
"The valleys have been considered almost timeless, yet here we see some changes that would be considered rapid even in more temperate climates," Fountain said.

These rapid changes over the past 14 years come at a time when the Antarctic climate may be turning a corner. While the Dry Valleys region was cooling locally during the 1990s and early 2000s, warmer summers followed. A major melt episode in the Antarctic summer of 2001-2002 set the stage for widespread melting in this polar desert landscape.

...

https://www.sciencedaily.com/releases/2018/10/181009135822.htm
Title: Re: What's new in Antarctica ?
Post by: gerontocrat on November 02, 2018, 09:24:00 PM
What's new in Antarctica ? Greed and stupidity displayed for all to see. The planet (that includes us) loses big-time again.

https://www.theguardian.com/world/2018/nov/02/plan-create-worlds-biggest-nature-reserve-antarctic-rejected

Antarctic's future in doubt after plan for world's biggest marine reserve is blocked
Environmental groups say Russia, China and Norway played part in rejecting plan

Quote
A plan to turn a huge tract of pristine Antarctic ocean into the world’s biggest sanctuary has been rejected, throwing the future of one of the Earth’s most important ecosystems into doubt.

Environmental groups said Russia, China and Norway had played a part in blocking the proposal, with the other 22 members of the Commission for the Conservation of Antarctic Marine Living Resources, the organisation set up to protect Antarctic waters, backing the proposal.

The 1.8m sq km reserve – five times the size of Germany – would have banned all fishing in a vast area of the Weddell Sea and parts of the Antarctic peninsula, safeguarding species including penguins, killer whales, leopard seals and blue whales.
Title: Re: What's new in Antarctica ?
Post by: Sleepy on November 03, 2018, 08:05:51 AM
Awful, a bit more on the individual "efforts" by Norway, China and Russia here:
https://www.greenpeace.org/international/press-release/19137/greenpeace-slams-antarctic-ocean-commission-for-failing-its-mandate-to-protect-antarctic-waters/ (https://www.greenpeace.org/international/press-release/19137/greenpeace-slams-antarctic-ocean-commission-for-failing-its-mandate-to-protect-antarctic-waters/)

And some memories:
Through its oil and gas exports, Norway is exporting 10 times more emissions than the country produces at home.
Norway is the world’s seventh largest exporter of emissions.
Norway’s proposed and prospective new oil and gas fields would lead to 150% more emissions than what is in currently operating fields.
Norway’s emissions trajectory with proposed and prospective new oil and gas fields is not in line with the rate of global emissions reduction needed to achieve the Paris goals.

Norway, world leader in using EV's and domestic hydro. Great little country, inside the borders.
Title: Re: What's new in Antarctica ?
Post by: RoxTheGeologist on November 03, 2018, 02:32:51 PM
Awful, a bit more on the individual "efforts" by Norway, China and Russia here:
https://www.greenpeace.org/international/press-release/19137/greenpeace-slams-antarctic-ocean-commission-for-failing-its-mandate-to-protect-antarctic-waters/ (https://www.greenpeace.org/international/press-release/19137/greenpeace-slams-antarctic-ocean-commission-for-failing-its-mandate-to-protect-antarctic-waters/)

And some memories:
Through its oil and gas exports, Norway is exporting 10 times more emissions than the country produces at home.
Norway is the world’s seventh largest exporter of emissions.
Norway’s proposed and prospective new oil and gas fields would lead to 150% more emissions than what is in currently operating fields.
Norway’s emissions trajectory with proposed and prospective new oil and gas fields is not in line with the rate of global emissions reduction needed to achieve the Paris goals.

Norway, world leader in using EV's and domestic hydro. Great little country, inside the borders.

Yes. They need a carbon tax, but then the oil wouldn't be competitive. Putting EVs on the road is no substitute for not taking carbon out of the ground.
Title: Re: What's new in Antarctica ?
Post by: oren on November 03, 2018, 02:43:23 PM
Well said Sleepy. The hypocrisy stinks to high heaven.
Title: Re: What's new in Antarctica ?
Post by: sidd on November 08, 2018, 09:05:32 PM
Putative lakes under Recovery prove elusive:

https://phys.org/news/2018-11-lakes-east-antarctic-ice-sheet.html

doi:10.1029/2017JF004591

open access

sidd
 
Title: Re: What's new in Antarctica ?
Post by: Sleepy on November 12, 2018, 12:40:31 PM
Iceberg flux from Antarctica from 1976-2017
https://twitter.com/PixelMnM/status/1061696386897530880 (https://twitter.com/PixelMnM/status/1061696386897530880)
Title: Re: What's new in Antarctica ?
Post by: gerontocrat on November 12, 2018, 12:45:24 PM
Iceberg flux from Antarctica from 1976-2017
Is it that the record is more complete in later years or has activity increased?
Title: Re: What's new in Antarctica ?
Post by: Sleepy on November 12, 2018, 01:32:59 PM
They don't provide the source in their tweet as you are able to read above, I would suspect it's from Budge an Long though. The Antarctic Iceberg Tracking Database.
Title: Re: What's new in Antarctica ?
Post by: vox_mundi on November 14, 2018, 05:18:09 PM
Discovery of High Geothermal Heat at South Pole
https://phys.org/news/2018-11-discovery-high-geothermal-south-pole.html

Scientists have discovered an area near the South Pole where the base of the Antarctic Ice Sheet is melting unexpectedly quickly. Using radar to look through three km of ice, the team found that some of the ice – covering an area that's twice the size of Greater London – appeared to be missing. The results are published this week in the journal Scientific Reports.

(https://media.springernature.com/m685/springer-static/image/art%3A10.1038%2Fs41598-018-35182-0/MediaObjects/41598_2018_35182_Fig1_HTML.png)

... The internal layer draw-down, supported by the highly-reflective bed, points to active and significant basal melting in this region.

... "The process of melting we observe has probably been going on for thousands or maybe even millions of years and isn't directly contributing to ice sheet change. However, in the future the extra water at the ice sheet bed may make this region more sensitive to external factors such as climate change."

Open Source: T. A. Jordan et al. Anomalously high geothermal flux near the South Pole (https://www.nature.com/articles/s41598-018-35182-0), Scientific Reports (2018).
Title: Re: What's new in Antarctica ?
Post by: Sleepy on November 14, 2018, 09:24:45 PM
"May" is an understatement.
Title: Re: What's new in Antarctica ?
Post by: Thomas Barlow on November 15, 2018, 04:02:35 AM
"Massive Antarctic iceberg spotted on NASA Operation IceBridge flight"
- NASA.
Before and after.
https://climate.nasa.gov/news/2827/massive-antarctic-iceberg-spotted-on-nasa-operation-icebridge-flight/?fbclid=IwAR3TS86kS9mXrAGJgFr7pBUIMloryjMVT5Vr2cLHH6iR3IbGSZQCVqac2To
Title: Re: What's new in Antarctica ?
Post by: Bernard on November 17, 2018, 11:18:20 AM
"Massive Antarctic iceberg spotted on NASA Operation IceBridge flight"
- NASA.
Before and after.
https://climate.nasa.gov/news/2827/massive-antarctic-iceberg-spotted-on-nasa-operation-icebridge-flight/?fbclid=IwAR3TS86kS9mXrAGJgFr7pBUIMloryjMVT5Vr2cLHH6iR3IbGSZQCVqac2To
Given the color of ice and melt water on the top image in this article, no wonder why this glacier is called PIG  ;D
Title: Re: What's new in Antarctica ?
Post by: sidd on November 19, 2018, 08:46:19 PM
Bronselaer et al. report on effect of increase ice melt from AIS on climate:

They find:

1)meltwater cools the southern hemisphere sufficiently to delay exceedance of tempertature targets by a decade
2)ITCZ and precip moves north,  enhanced drying of the Southern Hemisphere and reduced drying of the Northern Hemisphere
3)Increased subsea (deeper than 400m) warming aroung AIS increasing basal melt.

Unfortunately it seems CMIP6 does not include the effects discussed.

" The direct contribution from mass loss from the Antarctic Ice Sheet is already included in the IPCC assessments of future sea-level rise, although it is acknowledged to be highly uncertain in the fifth assessment report. However, the effect on climate is not included, and will not be in the upcoming CMIP6 experimental design. Similarly, the effects of meltwater from the Greenland Ice Sheet have so far not been considered, and
could lead to further changes in simulated future climate [Refs. 8,36]."

"Meltwater causes a reduction  in global atmospheric warming, delaying the realization of 1.5 °C and 2 °C warming by more than ten years; it drives a northward shift of the ITCZ, which results in reduced drying over Northern Hemisphere landmasses and enhanced drying in the Southern Hemisphere; and  it causes a large (up to 31%) increase in Antarctic sea-ice formation  relative to the pre-industrial period and an increase in subsurface  ocean warming around the Antarctic coast by a factor of four. Our results suggest that a feedback mechanism is in operation, whereby  the meltwater-induced subsurface warming leads to enhanced melting underneath ice shelves, potentially causing further meltwater-related climate effects. "

I notice Sergienko is an author. I attach fig 4. Paper is at doi: 10.1038/s41586-018-0712-z

coverage at

https://phys.org/news/2018-11-antarctic-atmospheric-sea.html

sidd