Support the Arctic Sea Ice Forum and Blog

Author Topic: What's new in Antarctica ?  (Read 176866 times)

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #500 on: July 30, 2019, 04:25:24 PM »
Glaciologists Unveil Most Precise Map Ever of Antarctic Ice Velocity
https://phys.org/news/2019-07-glaciologists-unveil-precise-antarctic-ice.html

Constructed from a quarter century's worth of satellite data, a new map of Antarctic ice velocity by glaciologists from the University of California, Irvine and NASA's Jet Propulsion Laboratory is the most precise ever created.

Published today in a paper in the American Geophysical Union journal Geophysical Research Letters, the map is 10 times more accurate than previous renditions, covering more than 80 percent of the continent.

To chart the movement of ice sheets across the surface of the enormous land mass, the researchers combined input from six satellite missions: the Canadian Space Agency's Radarsat-1 and Radarsat-2; the European Space Agency's Earth remote sensing satellites 1 and 2 and Envisat ASAR; and the Japan Aerospace Exploration Agency's ALOS PALSAR-1.

The new Antarctic ice velocity map and related datasets are available for download at the NASA Distributed Active Archive Center at the National Snow & Ice Data Center.



J. Mouginot et al. Continent‐wide, interferometric SAR phase, mapping of Antarctic ice velocity, Geophysical Research Letters (2019)
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

gerontocrat

  • First-year ice
  • Posts: 6528
    • View Profile
  • Liked: 1491
  • Likes Given: 21
Re: What's new in Antarctica ?
« Reply #501 on: July 30, 2019, 06:54:28 PM »
Pine Island and Thwaites.
I thought so.
E-mailed NASA-IceSat for clarification.

Will they answer? At least it was to a person not a corporate blah-blah address.
Last night e-mailed POTSDAM as well, asking about how could Ice-Sat and GRACE-FO data be combined with different basin definitions. Also said what a shame as combining the two sets of data would be such a powerful tool.

This morning did another internet search, and what did I find - they-ve done it already.

https://www.researchgate.net/publication/330380007_High-Resolution_Mass_Trends_of_the_Antarctic_Ice_Sheet_through_a_Spectral_Combination_of_Satellite_Gravimetry_and_Radar_Altimetry_Observations
High-Resolution Mass Trends of the Antarctic Ice Sheet through a Spectral Combination of Satellite Gravimetry and Radar Altimetry Observations - January 2019.

Yes, they combined GRACE & IceSat data.

Only goes to June 2017, but I assume the data will keep on coming.

So the first attachment is the 25 drainage basins used.

Then maps and a table.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Rich

  • Guest
Re: What's new in Antarctica ?
« Reply #502 on: July 30, 2019, 07:25:33 PM »
Wowzers!

This is one of the data trends more likely to be correlated with Armageddon.

Is there any sense of the frequency that data will be updated?

I'm a customer for sure. Thanks Gerontocrat.

gerontocrat

  • First-year ice
  • Posts: 6528
    • View Profile
  • Liked: 1491
  • Likes Given: 21
Re: What's new in Antarctica ?
« Reply #503 on: July 30, 2019, 07:44:23 PM »
In theory, GRACE-FO data every month.

But the combination with IceSat-2 stuff? The whole science world will want data from both places.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Rich

  • Guest
Re: What's new in Antarctica ?
« Reply #504 on: July 30, 2019, 07:59:42 PM »
Thanks G.

This is an exciting development. Mysterious parts of the world becoming less mysterious.

NASA released SLR figures for the 12 months ending 3/31/19 recently. 7.3mm. The hockey stick is emerging and it seems the day of reckoning is speeding up.

Data like this is going to reverberate in financial markets pretty fast.

With all due respect, I definitely appreciate the daily sea ice data, but it won't move markets the way land ice data will.

gerontocrat

  • First-year ice
  • Posts: 6528
    • View Profile
  • Liked: 1491
  • Likes Given: 21
Re: What's new in Antarctica ?
« Reply #505 on: July 31, 2019, 11:28:35 AM »
The GRACE-FO is a German / NASA joint project.

NASA have never answered a query yet.

Germany comes up with the goods every time.

Monthly Antarctic Ice Sheet data should be available in a Level 3 (i.e. simple ASCII format) in 2-3 weeks and every month after that, including by drainage basin. (Also for Greenland)

Level 2 stuff (not usable by me) is already there.

see attached...



"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

DrTskoul

  • Nilas ice
  • Posts: 1451
    • View Profile
  • Liked: 210
  • Likes Given: 60
Re: What's new in Antarctica ?
« Reply #506 on: July 31, 2019, 12:36:13 PM »
Glaciologists unveil most precise map ever of Antarctic ice velocity

More information: J. Mouginot et al. Continent‐wide, interferometric SAR phase, mapping of Antarctic ice velocity, Geophysical Research Letters (2019). DOI: 10.1029/2019GL083826

kassy

  • Grease ice
  • Posts: 755
    • View Profile
  • Liked: 272
  • Likes Given: 325
Re: What's new in Antarctica ?
« Reply #507 on: July 31, 2019, 06:14:54 PM »
So what is level 2? Data for specific programs or the visual output which can be manipulated like A-Team, Uniquorn and others do to some other satellites output?
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

DrTskoul

  • Nilas ice
  • Posts: 1451
    • View Profile
  • Liked: 210
  • Likes Given: 60
Re: What's new in Antarctica ?
« Reply #508 on: July 31, 2019, 06:15:45 PM »
Yeah...

Renerpho

  • New ice
  • Posts: 37
    • View Profile
  • Liked: 32
  • Likes Given: 13
Re: What's new in Antarctica ?
« Reply #509 on: July 31, 2019, 07:45:12 PM »
So what is level 2? Data for specific programs or the visual output which can be manipulated like A-Team, Uniquorn and others do to some other satellites output?

It is raw gravity data, in a txt file. See ftp://isdcftp.gfz-potsdam.de/grace-fo/DOCUMENTS/Level-2/GRACE-FO_JPL_L2_Processing_Standards_Document_for_RL06.pdf for a description of the content, https://pdfs.semanticscholar.org/a906/232145ab2a7a48d87461abd48a3170ee0dae.pdf for an introduction to spherical harmonic analysis. You get the coefficients C_ml and S_ml, up to order 180. Putting it into a formula will give you a latitude/longitude map of the gravity field, which then needs to be interpreted.
The data itself can be found here, sorted by time interval: ftp://isdcftp.gfz-potsdam.de/grace-fo/Level-2/JPL/RL06/ I guess the logic behind the file names is YYYY"day of year"-YYYY"day of year"_"some stuff".gz, but I didn't bother to read the manual. It should all be in there.

Ah, by the way: Hello ASIF! This is my first post. I have been reading here for a while. I hope I'm not interrupting, and you find the explanation useful.

-- Daniel
Before I came here I was confused about this subject. Having listened to your lecture I am still confused. But on a higher level.

SteveMDFP

  • Nilas ice
  • Posts: 1436
    • View Profile
  • Liked: 182
  • Likes Given: 15
Re: What's new in Antarctica ?
« Reply #510 on: July 31, 2019, 07:58:18 PM »
The GRACE-FO is a German / NASA joint project.

NASA have never answered a query yet.

Germany comes up with the goods every time.
 

Increasingly, Federal employees have to go through layers of approval before sending any communications to members of the general public.  This seems to be especially true for agencies involved with climate and the environment. 

nanning

  • Grease ice
  • Posts: 864
  • 0Kg CO2, 35 KWh/wk,130L H2O/wk, No heating
    • View Profile
  • Liked: 133
  • Likes Given: 5685
Re: What's new in Antarctica ?
« Reply #511 on: August 01, 2019, 04:28:26 AM »
<snippage>
Ah, by the way: Hello ASIF! This is my first post. I have been reading here for a while. I hope I'm not interrupting, and you find the explanation useful.

-- Daniel
Welcome to the forum Daniel and thanks for your informative contribution.
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
   Simple: minimize your possessions and be free and kind    It's just a mindset.       Refugees welcome

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #512 on: August 03, 2019, 05:35:06 PM »
US Eyeing Militarization of Antarctic as Well as Arctic
https://www.commondreams.org/news/2019/07/31/us-eyeing-militarization-antarctic-well-arctic

A top U.S. military general said Tuesday that the country will be looking at militarizing the Antarctic just as it has the Arctic.

Air Force general Charles Brown, commander of Pacific Air Force, made the remarks in an address at The Mitchell Institute for Aerospace Studies in Arlington, Virginia.




... At several points, Brown mentioned 2048, which is set to be a key moment for the Antarctic—a region "within increasingly convenient reach"—because it's when the Antarctic Treaty can go under review.

He added that icebreakers were a lacking capability—"Russia has much more than we do." And, because the U.S. military will still need the few it has to operate in the Arctic, "we may need more" to bring them to Antarctica. (... ya think)

As geopolitics professor Klaus Dodds wrote at The Conversation last year, the looming review plunges "the future of the continent into uncertainty."

Quote
... For six decades, the treaty has been the cornerstone of governance for our most southerly, harshest and most pristine continent. It has fostered scientific research, promoted international cooperation, ensured non-militarization, suspended territorial claims and strengthened environmental protections. Its guardians are the Antarctic Treaty Consultative Parties (ATCPs)—chief among them the U.S., U.K., Australia, New Zealand, Russia, Norway, Germany, Chile, and Argentina. [...]

At present ACTPs are focusing on improving cold weather technology and gaining confidence in Antarctic conditions, but it might not be long until they have the capability and incentive to do more. China is already using underwater vehicles to search for gas hydrates and metallic nodules in the South China Sea. Ominously, underwater mining and deep-sea energy prospecting seem set to be growth industries over the coming decades. [...]

After 2048, Antarctica could be carved up between nations like every other land mass and surrounding ocean, and slowly relieved of its resources.
« Last Edit: August 03, 2019, 11:56:03 PM by vox_mundi »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

zxy

  • New ice
  • Posts: 9
    • View Profile
  • Liked: 14
  • Likes Given: 0
Re: What's new in Antarctica ?
« Reply #513 on: August 05, 2019, 01:18:30 AM »
Interesting documentary on current state:

The State of Sea Level Rise (2019)

nanning

  • Grease ice
  • Posts: 864
  • 0Kg CO2, 35 KWh/wk,130L H2O/wk, No heating
    • View Profile
  • Liked: 133
  • Likes Given: 5685
Re: What's new in Antarctica ?
« Reply #514 on: August 05, 2019, 07:57:36 PM »
"It is preoccupation with possessions, more than anything else, that prevents us from living freely and nobly" - Bertrand Russell
   Simple: minimize your possessions and be free and kind    It's just a mindset.       Refugees welcome

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #515 on: August 06, 2019, 05:51:28 PM »
Saildrone Completes First Autonomous Scientific Trip Around Antarctica
https://futurefive.co.nz/story/saildrone-completes-first-unmanned-trip-around-antarctica
https://www.bloomberg.com/news/articles/2019-08-05/saildrone-s-journey-around-antarctica-uncovers-new-climate-clues 

Saildrone’s wind-powered surface vehicle (called SD 20) is seven metres long and is now the world’s first unmanned vehicle to circumnavigate Antarctica.



... This mission wasn’t just to prove that you could sail an unmanned vehicle around Antarctica – it also had a lot of scientific equipment and partners.

SD 20 was equipped with a suite of climate-grade sensors and collected data in previously unchartered waters, enabling new key insights into ocean and climate processes.

The Saildrone also carried an instrument developed by National Atmospheric and Oceanographic Administration (NOAA) to measure carbon fluxes.

Quote
... The saildrone recorded evidence that the Southern Ocean released significant carbon dioxide during the winter months a fact that could have major implications on global climate models.

Thus the Southern Ocean might not be storing nearly as much carbon as previously thought .... Scientists have long viewed the Southern Ocean as a major carbon sink, meaning it pulls carbon dioxide out of the air and pushes it deep underwater.



https://www.saildrone.com/

-----------------------------

Related from 2018: Diving Robots Find Antarctic Winter Seas Exhale Surprising Amounts of Carbon Dioxide
https://phys.org/news/2018-08-robots-antarctic-winter-seas-exhale.html

A new study from the University of Washington, the Monterey Bay Aquarium Research Institute, Princeton University and several other oceanographic institutions uses data gathered by the floating drones over past winters to learn how much carbon dioxide is transferred by the surrounding seas. Results show that in winter the open water nearest the sea ice surrounding Antarctica releases significantly more carbon dioxide than previously believed.
Quote
... "These results came as a really big surprise, because previous studies found that the Southern Ocean was absorbing a lot of carbon dioxide," said . "If that's not true, as these data suggest, then it means we need to rethink the Southern Ocean's role in the carbon cycle and in the climate."

- lead author Alison Gray - UW Assistant Professor of Oceanography
The paper is published Aug. 14 in Geophysical Research Letters.

Looking at circles of increasing distance from the South Pole, the authors find that in winter the open water next to the sea-ice covered waters around Antarctica is releasing significantly more carbon dioxide than expected to the atmosphere.

"It's not surprising that the water in this region is outgassing, because the deep water is exceptionally rich in carbon," Gray said. "But we underestimated the magnitude of the outgassing because we had so little data from the winter months. That means the Southern Ocean isn't absorbing as much carbon as we thought."

https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078013
« Last Edit: August 07, 2019, 06:05:51 PM by vox_mundi »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

petm

  • Grease ice
  • Posts: 675
    • View Profile
  • Liked: 334
  • Likes Given: 27
Re: What's new in Antarctica ?
« Reply #516 on: August 08, 2019, 04:25:03 AM »
Quote
Stunning drone footage captures Chasm 1, a huge crack on the Brunt Ice Shelf. When it inevitably intersects with the nearby Halloween Crack, an iceberg the size of Houston, Texas will break off into the ocean.


gerontocrat

  • First-year ice
  • Posts: 6528
    • View Profile
  • Liked: 1491
  • Likes Given: 21
Re: What's new in Antarctica ?
« Reply #517 on: August 10, 2019, 09:25:07 AM »
Not that new but I had completely forgotten to follow a link to.........

https://www.pnas.org/content/116/4/1095
Four decades of Antarctic Ice Sheet mass balance from 1979–2017


Open access,  with downloadable
- pdf,
- excel spreadsheet,
- figures (attached),
- tables (summary one attached)

A stunning piece of work.

Quote
Results
Antarctica.

The total mass loss from Antarctica increased from 40 ± 9 Gt/y in the 11-y time period 1979–1990 to 50 ± 14 Gt/y in 1989–2000, 166 ± 18 Gt/y in 1999–2009, and 252 ± 26 Gt/y in 2009–2017, that is, by a factor 6 (Fig. 2, Table 1, and SI Appendix, Fig. S1). This change in mass loss reflects an acceleration of 94 Gt/y per decade in 1979–2017, increasing from 48 Gt/y per decade in 1979–2001 to 134 Gt/y per decade in 2001–2017, or 280%. Most of the 1979–2017 acceleration is from West Antarctica (48 Gt/y per decade), followed by East Antarctica (29 Gt/y per decade) and the Antarctic Peninsula (16 Gt/y per decade) (Fig. 3). In 2009–2017, West Antarctica contributed 63% of the total loss (159 ± 8 Gt/y), East Antarctica 20% (51 ± 13 Gt/y), and the Peninsula 17% (42 ± 5 Gt/y) (Table 2). The mass loss from West Antarctica is three to four times larger than that from East Antarctica and the Peninsula, respectively. We find that the Antarctic Ice Sheet has been out of balance with snowfall accumulation the entire period of study, including in East Antarctica.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #518 on: August 12, 2019, 06:37:51 PM »
Icebergs Delay Southern Hemisphere Future Warming
https://phys.org/news/2019-08-icebergs-southern-hemisphere-future.html


Future iceberg discharges from the disintegrating West Antarctic ice-sheet (lower right inlay figure) can lead to a substantial reduction of human-induced warming in the Southern Hemisphere. Anthropogenic warming averaged over the pink shaded region without iceberg effect (black) and for weak (cyan), medium (blue) and strong (dark blue) iceberg discharge scenarios. The other two inlay figures depict the iceberg effect on human-induced warming for the model grid points closest to Buenos Aires (Argentina, orange) and Cape Town (South Africa, green).

New research, published today in the journal Nature Climate Change, has found that Antarctic icebergs can weaken and delay the effect of Global Warming in the Southern Hemisphere.

Recent observations reveal a rapid thinning of the Pine Island and Thwaites glacier regions in Antarctica, which can be attributed partly to warming oceans. These findings have raised concerns of an accelerated ice loss of the West Antarctic ice sheet and potential contributions to global sea level rise. Ice loss can occur in the form of melt-induced (liquid) freshwater discharge into the ocean, or through (solid) iceberg calving.

With a projected future retreat of the Antarctic ice sheet, scientists expect an intensification of iceberg discharge. Icebergs can persist for years and are carried by winds and currents through the Southern Ocean until they reach warmer waters and ultimately melt. The melting process cools ocean waters like ice cubes in a cocktail glass. Furthermore, freshwater discharge from icebergs impacts currents by lowering ocean salinity. Whether this "iceberg effect'' can slow down or alter future climate change in the Southern Hemisphere has remained an open question.

Climate researchers from the University of Hawaii (USA), the IBS Center for Climate Physics (South Korea), Penn State University (USA) and University of Massachusetts (USA) have now quantified for the first time this effect of Antarctic iceberg calving on future Southern Hemisphere climate. The team ran a series of Global Warming computer simulations, which include the combined freshwater and cooling effects of icebergs on the ocean. The size and number of icebergs released in their model mimics the gradual retreat of the Antarctic ice sheet over a period of several hundred years. By turning on an off the "iceberg effect" in their climate model, the researchers discovered that icebergs can significantly slow down human-induced warming in the Southern Hemisphere, impacting global winds and rainfall patterns.

Dr. Tobias Friedrich, coauthor of the study, adds: "To melt the icebergs released over the 21st century in one of our extreme Antarctic ice-sheet retreat scenarios would require 400 times the current annual world energy consumption. Global sea level would rise by about 80 cm, impacting many coastal regions and communities worldwide."

"Our research highlights the role of icebergs in global climate change and sea level rise. Depending on how quickly the West Antarctic ice sheet disintegrates, the iceberg effect can delay future warming in cities such as Buenos Aires and Cape Town by 10-50 years." says Prof. Axel Timmermann, corresponding author of the study and Director of the IBS Center for Climate Physics.

Antarctic iceberg impacts on future Southern Hemisphere climate, Nature Climate Change (2019)
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

petm

  • Grease ice
  • Posts: 675
    • View Profile
  • Liked: 334
  • Likes Given: 27
Re: What's new in Antarctica ?
« Reply #519 on: August 12, 2019, 06:43:15 PM »
Business opportunity: Tow giant icebergs up to northern coastal cities and moor them near shore.

philopek

  • Frazil ice
  • Posts: 438
    • View Profile
  • Liked: 156
  • Likes Given: 40
Re: What's new in Antarctica ?
« Reply #520 on: August 12, 2019, 06:58:27 PM »
Business opportunity: Tow giant icebergs up to northern coastal cities and moor them near shore.

But use a wind-powered or battery driven vessel for the purpose please  8)

Tom_Mazanec

  • Nilas ice
  • Posts: 1500
    • View Profile
    • Planet Mazanec
  • Liked: 327
  • Likes Given: 55
Re: What's new in Antarctica ?
« Reply #521 on: August 13, 2019, 03:03:04 AM »
Global Warming is changing the winds off Antarctica, which is accelerating ice loss of WAIC
(pushes warmer water under the ice):
https://insideclimatenews.org/news/12082019/antarctica-climate-change-ocean-wind-ice-melting-glaciers-global-warming
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

Tor Bejnar

  • Young ice
  • Posts: 3041
    • View Profile
  • Liked: 361
  • Likes Given: 187
Re: What's new in Antarctica ?
« Reply #522 on: August 13, 2019, 06:50:29 PM »
Business opportunity: Tow giant icebergs up to northern coastal cities and moor them near shore.
You could have referenced
Towing an Iceberg: One Captain’s Plan to Bring Drinking Water to 4 Million People or similar articles.
Arctic ice is healthy for children and other living things.

Stephen

  • Frazil ice
  • Posts: 109
    • View Profile
  • Liked: 10
  • Likes Given: 0
Re: What's new in Antarctica ?
« Reply #523 on: August 14, 2019, 05:07:02 AM »
Towing Icebergs?  it's been done...
https://struckbyenlightning.wordpress.com/2009/11/30/sydney-iceberg-89-hoax/

But seriously, the thing that all of these schemes underestimate is the cost of the energy used to construct or implement the idea.  There was a kid in my high school science classes who was forever coming up with perpetual motion machines.  He never considered or understood entropy or friction.  I put damming the Bering Straits and towing icebergs in the same category as perpetual motion machines.

Just use solar & wind to generate the power to desalinate sea-water.  Quicker, cheaper, more permanent solution using currently available technologies.
The ice was here, the ice was there,   
The ice was all around:
It crack'd and growl'd, and roar'd and howl'd,   
Like noises in a swound!
  Rime of the Ancient Mariner by Samuel Taylor Coleridge

KiwiGriff

  • Frazil ice
  • Posts: 230
    • View Profile
  • Liked: 112
  • Likes Given: 0
Re: What's new in Antarctica ?
« Reply #524 on: August 14, 2019, 11:13:34 PM »
More on the paper mentioned by Tom_Mazanec above.

The Antarctic ice sheet is melting and, yeah, it’s probably our fault.
Filed under: Climate Science — eric @ 14 August 2019
Glaciers in West Antarctica have thinned and accelerated in the last few decades.  A new paper provides some of the first evidence that this is due to human activities.
http://www.realclimate.org/index.php/archives/2019/08/the-antarctic-ice-sheet-is-melting-and-yeah-its-probably-our-fault/
I will not try to condense what is a complex topic. Please read Eric's explanation.

Rodius

  • Frazil ice
  • Posts: 108
    • View Profile
  • Liked: 58
  • Likes Given: 4
Re: What's new in Antarctica ?
« Reply #525 on: September 03, 2019, 01:43:17 PM »
I dont know where else to put this..... but this seems about right.

Sudden stratospheric warming over the south pole, rising temperatures more than 40°C above normal.

http://www.severe-weather.eu/recent-events/sudden-stratospheric-warming-antarctica/?fbclid=IwAR2VVB_LoyexBNxy3HdTvB2jQELo8wxM_5ewWqaJH4TW-BDX69FTvdgPpds

kassy

  • Grease ice
  • Posts: 755
    • View Profile
  • Liked: 272
  • Likes Given: 325
Re: What's new in Antarctica ?
« Reply #526 on: September 03, 2019, 01:51:07 PM »
Vintage film reveals Antarctic glaciers are melting faster than thought

...

now, scientists from Stanford, Cambridge, Imperial College London and the University of Edinburgh have widened the window back to the early 1970s.

The team has digitized old film reels of data gathered between 1971 and 1979. This data was the result of around 250,000 miles (400,000 km) of flights across Antarctica during that decade, using ice-penetrating radar to examine the structure of the ice and the landscape beneath it.

By comparing the measurements taken back then to those gathered more recently, the team was able to get a sense of how much had changed in the intervening 40 to 50 years.

...

The researchers found that the old data was surprisingly detailed, allowing them to identify features like ash layers from past volcanic eruptions, and channels underneath the ice sheet where water is eroding the ice.

In particular, one of these channels was found to have remained fairly stable over the last 40 years – Thwaites, on the other hand, appears to have lost even more ice than previously thought, shrinking by up to a third between 1978 and 2009. And because the stable channel provides a good baseline comparison, the researchers can be more sure about the results.

...

https://newatlas.com/environment/vintage-film-antarctic-glaciers-melting-faster/
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

gerontocrat

  • First-year ice
  • Posts: 6528
    • View Profile
  • Liked: 1491
  • Likes Given: 21
Re: What's new in Antarctica ?
« Reply #527 on: September 03, 2019, 02:36:15 PM »
I dont know where else to put this..... but this seems about right.

Sudden stratospheric warming over the south pole, rising temperatures more than 40°C above normal.

http://www.severe-weather.eu/recent-events/sudden-stratospheric-warming-antarctica/?fbclid=IwAR2VVB_LoyexBNxy3HdTvB2jQELo8wxM_5ewWqaJH4TW-BDX69FTvdgPpds
Spectacular Images on the link
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Tom_Mazanec

  • Nilas ice
  • Posts: 1500
    • View Profile
    • Planet Mazanec
  • Liked: 327
  • Likes Given: 55
Re: What's new in Antarctica ?
« Reply #528 on: September 04, 2019, 07:39:21 PM »
Too bad I live in the Northern Hemisphere  ;D
Icebergs Could Delay Effects Of Climate Change By 50 Years In Southern Hemisphere
https://www.hawaiipublicradio.org/post/icebergs-could-delay-effects-climate-change-50-years-southern-hemisphere#stream/0
Quote
In order to quantify the impact of icebergs on climate change, researchers ran multiple global warming simulations to include the freshwater and cooling effects of icebergs on the ocean. Researchers also factored in the size and number of icebergs released in the model to mimic the retreat of the Antarctic ice sheet.

Researchers compared the difference between the two models, and found the role icebergs could play in delaying the effects of human-induced warming in the Southern Hemisphere.
SHARKS (CROSSED OUT) MONGEESE (SIC) WITH FRICKIN LASER BEAMS ATTACHED TO THEIR HEADS

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: What's new in Antarctica ?
« Reply #529 on: September 17, 2019, 08:29:55 PM »
Emperors on thin ice: three years of breeding failure at Halley Bay

https://www.cambridge.org/core/journals/antarctic-science/article/emperors-on-thin-ice-three-years-of-breeding-failure-at-halley-bay/4CA1A77971A4CD5D5CB823EBF338FAA9/core-reader


Abstract

Satellite imagery is used to show that the world's second largest emperor penguin colony, at Halley Bay, has suffered three years of almost total breeding failure. Although, like all emperor colonies, there has been large inter-annual variability in the breeding success at this site, the prolonged period of failure is unprecedented in the historical record. The observed events followed the early breakup of the fast ice in the ice creeks that the birds habitually used for breeding. The initial breakup was associated with a particularly stormy period in September 2015, which corresponded with the strongest El Niño in over 60 years, strong winds, and a record low sea-ice year locally. Conditions have not recovered in the two years since. Meanwhile, during the same three-year period, the nearby Dawson-Lambton colony, 55 km to the south, has seen a more than tenfold increase in penguin numbers. The authors associate this with immigration from the birds previously breeding at Halley Bay. Studying this ‘tale of two cities’ provides valuable information relevant to modelling penguin movement under future climate change scenarios.

Introduction
The emperor penguin (Aptenodytes forsteri Gray) colony at Halley Bay (75°33′S, 27°32′W) was one of the largest colonies in Antarctica, second only in size to that at Coulman Island in the Ross Sea (Fretwell et al. 2012). The colony is located on the northern side of the Brunt Ice Shelf (Fig. 1) and, for the past two decades, has been situated in a bay, locally named ‘Windy Creek’. Although no organized science has been conducted on the colony, it has been visited by staff from the Halley Research Station sporadically from 1956–2012 and estimates of size vary between approximately 14 300–23 000 pairs (Woehler 1993, British Antarctic Survey (BAS) unpublished data, H.J. Gillett personal communication 2018). It is likely that the colony is associated with foraging on the shallow McDonald Bank and McDonald Ice rumples, to the north and east of the site and the coastal polynya that forms north of the Brunt Ice shelf each summer season (Hodgson et al. 2018). Although this polynya is a consistent feature, the sheltered bays bordering the ice shelf usually retain fast ice until December and often the ice remains all summer. This ensures that emperors are able to raise their chicks at the site as their young fledge between mid-December and early January.


Fig. 1. Overview of the Brunt Ice Shelf, showing the location of Halley Bay and Dawson-Lambton emperor penguin colonies. The underlying image is a Landsat8 image from October 2016.

Although the recorded population has varied, the colony is consistently the largest in the Weddell Sea, over twice the size of any other colony in the region. There have been no previously recorded instances of total breeding failure at the site. It possibly represents 6.5–8.5% of the total global population and, as it is situated at high latitudes, it plausibly represents an important climate change refugia (Ainley et al. 2010, Jenouvrier et al. 2017).
The nearest colony to the Halley site is the Dawson-Lambton colony, some 55 km to the south, located where the Brunt Ice Shelf joins the continental coast (Fig. 1). Geographically this is an unusually small distance between emperor colonies (Ancel et al. 2017). Only the Mertz Ice Shelf colonies have a smaller distance between them, and these two colonies originated from a single site before the recent calving of the Mertz Ice Tongue in 2010 (Ancel et al. 2014).
However, recent monitoring has shown that the Halley Bay colony has suffered catastrophic breeding failure, whilst the nearby Dawson-Lambton colony has markedly increased in size. In this paper very high resolution (VHR) satellite imagery is used to estimate population changes at the two sites over the last ten years.

The exact number is difficult to estimate due to the rough ice surface confusing the automated image analysis. The best estimate is that around five times more birds were at, or within ~100 m of the sea-ice edge than at the main colony site. Many of the penguins were on refrozen brash ice or newly formed grease ice. This does not include the lines of birds moving between the colony site and the ice edge, which can easily be identified as birds in transit. Emperors do not breed or habitually feed their young at the ice edge as its position is dynamic and the high risk of breakup would pose a danger to unfledged chicks. Whether the adult birds here were failed breeders or non-breeders is difficult to assess from imagery alone. Subsequent Landsat8 and Sentinel2 imagery shows that by 29 November 2018, all of the fast ice on the north side of the Brunt Ice Shelf had gone, highlighting a third year of probable total breeding failure. These assumed failed breeding events are of a scale that is not apparent in the long, but sporadic record from the site (H.J. Gillett personal communication 2018, BAS records).


Fig. 2. Variability in the emperor penguin population breeding at Windy Creek, Halley Bay (solid line), and Dawson-Lambton colony (dashed line). Estimates made from very high resolution satellite imagery following the methods of Fretwell et al. (2012); upper and lower 95% confidence intervals are shown.

Understanding how environmental drivers, such as changes in SAM, sea ice, or wind speed, direction and velocity, impact upon the breeding colony at Halley, or indeed elsewhere, remains a key challenge. Further, exploring how extremes of such events lead to breeding failure is vital for projecting future population trajectories in a warming environment. The relationship between climate change and El Niño events, or positive SAM anomalies is still a matter of active research (Trenberth & Hoar 1997, Turner 2004, Turner et al. 2005, Yeh et al. 2009, Collins et al. 2010, Bracegirdle 2013, Cai et al. 2015). Recent research suggests that the frequency of El Niño and La Niña events are predicted to increase, while ENSO-related catastrophic weather events are also likely to occur more frequently with unabated greenhouse gas emissions (Cai et al. 2015). However, other evidence cautions that it is not yet possible to say whether ENSO activity will be enhanced or damped, or if the frequency of events will change (Collins et al. 2010). The evidence from observations of the present authors, and from earlier papers (Kooyman et al. 2007, Ancel et al. 2014), points to the fact that stochastic impacts upon emperors may be vital, even for high-latitude locations. Strong winds, or storm events can create coastal leads or polynyas that are beneficial to foraging, but prolonged periods of extreme winds can also lead to breakup and dissipation of fast ice, which can cause total breeding failure when it occurs at a sensitive time for the penguins.
At Halley, another important factor influencing the stability of the fast ice around the colony could be the dynamic nature of the creek in which it is located. Until recently, the colony was situated within a sheltered ice creek, on the northern side of the Brunt Ice Shelf, informally named Windy Creek. Over the past 60 years, the colony has occasionally moved to other adjacent sheltered creeks (H.J. Gillett personal communication 2018, BAS records). With the fast-ice breakout in 2016, ice shelf morphology changed (Fig. 3) and the resulting more open nature of the creek may now be less suitable for fast-ice retention. The Brunt Ice Shelf is a fast-moving and dynamic environment (Hodgson et al. 2018). Over the last two decades the creek has gradually moved westwards by over 600 m per year and it is possible that the migration and changing topography of Windy Creek has made it a less favourable site for emperor penguins. Any future breeding at Halley will almost certainly depend upon the juxtaposition of sheltered, stable fast ice, foraging opportunities, including over the nearby McDonald Bank, and the longer-term processes that will happen once the Brunt Ice Shelf calves, which at present rates will be within the next two years.


Fig. 3. Medium resolution satellite imagery of the Windy Creek breeding site for the years between spring 2015 and spring 2018.

Conclusion
The authors describe an unprecedented three-year period of breeding failure at the large Halley Bay emperor penguin colony. They link this to a dramatic rise in the population of the nearby Dawson-Lambton colony, a rise that can only have occurred due to immigration from Halley. These changes have been driven by a change in sea-ice conditions and early breakup of fast ice on the northern side of the Brunt Ice Shelf, which may be due to ENSO events and/or ice-shelf morphology.
In a warming world, it will be crucial to better understand the interplay between wind and ice shelf orography, and to appreciate how these factors impact the location of emperor penguin colonies. Understanding how emperor penguins react to catastrophic sea-ice loss will be of crucial importance if one is to predict the fate of the species over coming decades.

bligh


Stephan

  • Grease ice
  • Posts: 757
    • View Profile
  • Liked: 230
  • Likes Given: 126
Re: What's new in Antarctica ?
« Reply #530 on: September 17, 2019, 10:39:53 PM »
Thank you for sharing this information with us.
I think the more you know the more complicated it gets. Thinking of ice extent or melt ponds areas alone does not describe the full picture. All the impacts on animals' population or habitats should be examined in greater detail in general. This should also help in a better multidisciplinary understanding on the implications of AGW in general.
It is too late just to be concerned about Climate Change

bligh8

  • Frazil ice
  • Posts: 310
    • View Profile
  • Liked: 57
  • Likes Given: 4
Re: What's new in Antarctica ?
« Reply #531 on: September 17, 2019, 11:32:51 PM »
Thanks ;)  I fear for these lovely creatures....

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #532 on: September 20, 2019, 06:43:30 PM »
Surface Melting Causes Antarctic Glaciers to Slip Faster Towards the Ocean, New Research Shows
https://phys.org/news/2019-09-surface-antarctic-glaciers-faster-ocean.html

Surface meltwater draining through the ice and beneath Antarctic glaciers is causing sudden and rapid accelerations in their flow towards the sea, according to new research

Using imagery and data from satellites alongside regional climate modeling, scientists at the University of Sheffield have found that meltwater is causing some glaciers to move at speeds 100 percent faster than average (up to 400m per year) for a period of several days multiple times per year.

The new research, published today in Nature Communications, shows that accelerations in Antarctic Peninsula glaciers' movements coincide with spikes in snowmelt. This association occurs because surface meltwater penetrates to the ice bed and lubricates glacier flow.

The effects of such a major shift in Antarctic glacier melt on ice flow has not yet been incorporated into the models used to predict the future mass balance of the Antarctic Ice Sheet and its contribution to sea level rise.



Open Access: Peter A. Tuckett et al. Rapid accelerations of Antarctic Peninsula outlet glaciers driven by surface melt, Nature Communications (2019)
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #533 on: October 30, 2019, 11:01:45 PM »
Two Million-Year-Old Ice Provides Snapshot of Earth's Greenhouse Gas History
https://phys.org/news/2019-10-million-year-old-ice-snapshot-earth-greenhouse.html



In a paper published today in Nature, a group of scientists used air trapped in the bubbles in ice as old as 2 million years to measure levels of the greenhouse gases carbon dioxide and methane.

... During the past one million years the cycle of ice ages followed by warm periods occurred every 100,000 years. But between 2.8 million years ago and 1.2 million years ago, those cycles were shorter, about 40,000 years, and ice ages were less extreme.

They found that the highest levels of carbon dioxide matched the levels in warm periods of more recent times. The lowest levels, however, did not reach the very low concentrations found in the ice ages of the last 800,000 years. ...

Yuzhen Yan, et.al. Two-million-year-old snapshots of atmospheric gases from Antarctic ice, Nature (2019)
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

Adam Ash

  • Frazil ice
  • Posts: 306
    • View Profile
    • The 100 metre line
  • Liked: 8
  • Likes Given: 20
Re: What's new in Antarctica ?
« Reply #534 on: October 31, 2019, 11:45:06 AM »
Surface Melting Causes Antarctic Glaciers to Slip Faster Towards the Ocean, New Research Shows
https://phys.org/news/2019-09-surface-antarctic-glaciers-faster-ocean.html

Surface meltwater draining through the ice and beneath Antarctic glaciers is causing sudden and rapid accelerations in their flow towards the sea, according to new research
...
...This association occurs because surface meltwater penetrates to the ice bed and lubricates glacier flow.

(My emphasis)

I would assume that the beds of these portions of the glaciers are well below sea level, and that the beds are already flooded, with the minimum free water surface being equal to sea level (or higher if trapped).  Therefore one would imagine that the meltwater can only trickle down to sea level, no further.  The bed cannot get 'wetter' or more 'lubricated'  than it already is. 

So is it not more plausible that the meltwater is causing an increase in the height of the free water surface surrounding portions of the glacier, and it is thus giving rise to uplift (floatation) of the glacier locally, reducing its contact with the bed, thus allowing increased speed of travel towards the sea?

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #535 on: October 31, 2019, 12:10:39 PM »
Adam - What you are describing is true for a grounded ice shelf. But the study refers to the Drygalski Glacier, Antarctic Peninsula and it's base is above sea level.
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

kassy

  • Grease ice
  • Posts: 755
    • View Profile
  • Liked: 272
  • Likes Given: 325
Re: What's new in Antarctica ?
« Reply #536 on: October 31, 2019, 02:42:57 PM »
re 533
a short quote from the sciencemag article on the results from this ice core:

When the team looked at CO2 levels from 1.5 million years ago, they found them on average quite similar to the postflip world, swinging between 204 and 289 ppm, depending on whether the world was in an ice age or not. “It’s surprising,” Yan says, given broad evidence that the world was warmer in the early Pleistocene, before the ice ages grew deeper. “The educated guess is you’d have higher CO2 to achieve that. But that’s not something we see.”

That means that something other than CO2 was likely driving the cooling, says Peter Clark, a glaciologist at Oregon State University in Corvallis. One such driver could be the cumulative buildup of ice across the Northern Hemisphere; such ice would reflect sunlight back into space, cooling the atmosphere. Clark has long advanced a hypothesis that repeated glaciations gradually scoured away soil and other loose grit that would have prevented ice from “sticking” to bedrock. Once that grit was gone, the anchored ice sheets could thicken and grow to a tipping point, sending the planet into 100,000-year cycles.


https://www.sciencemag.org/news/2019/10/world-s-oldest-ice-core-could-solve-mystery-flipped-ice-age-cycles
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #537 on: November 04, 2019, 04:24:57 PM »
Revealing Interior Temperature of Antarctic Ice Sheet
https://phys.org/news/2019-11-revealing-interior-temperature-antarctic-ice.html

ESA’s SMOS mission has been used to show how the temperature of the Antarctic ice sheet changes with depth. The image shows how the ice is colder (blue) at the surface but warmer (red) at the base. Temperature is one of the things that determines how ice flows and slides over the bedrock beneath. In turn, this flow affects the temperature profile through strain heating – so it’s a complicated process. Temperature information is also fundamental for understanding the presence of aquifers inside or at the bottom part of ice sheets. This can be relevant for indicating the presence of sub-glacial lakes, for example, which in turn influence ice-sheet dynamics.

... "We combined SMOS' L-band passive microwave observations over Antarctica with glaciological and emission models to infer information on glaciological properties of the ice sheet at various depths, including temperature"



Giovanni Macelloni et al. On the retrieval of internal temperature of Antarctica Ice Sheet by using SMOS observations, Remote Sensing of Environment (2019)
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

vox_mundi

  • Nilas ice
  • Posts: 1613
    • View Profile
  • Liked: 618
  • Likes Given: 111
Re: What's new in Antarctica ?
« Reply #538 on: November 06, 2019, 06:15:05 PM »
Persistent Drizzle at Sub-Zero Temps in Antarctica
https://phys.org/news/2019-11-persistent-drizzle-sub-zero-temps-antarctica.html

Using both ground-based and satellite measurements, researchers recorded drizzle conditions below minus 13 degrees Fahrenheit lasting for more than 7.5 hours at McMurdo Station, Antarctica. Previous reports recorded supercooled drizzle at these temperatures, but only for brief durations. The presence of drizzle over several hours could have some implications for climate model predictions. The researchers published their findings in the Journal of Geophysical Research: Atmospheres.

"Drizzle should be properly simulated in models because it removes water from the cloud layer when droplets combine with one another and eventually fall," Silber said. "That means drizzle would affect the cloud's lifetime, which would influence the amount of heat reaching the Earth's surface."

... Meteorologists define drizzle as water droplets smaller than 0.5 millimeters in diameter, or about one-fiftieth of an inch. According to Silber, drizzle and rain are treated interchangeably in climate models given that both are in a liquid phase, compared to other hydrometeors, such as snow and hail.

... Using the simulations, the researchers found that low concentrations of some types of particles suspended in the Earth's atmosphere, such as sea-salt and dust, were highly conducive to drizzle formation.

"In Antarctica, the air is very clean," said Silber. "There are fewer pollutants, and therefore fewer airborne particles."

The low concentration of these particles allowed the drizzle to remain in liquid form, even though the air temperatures were well below freezing.

Israel Silber et al, Persistent Supercooled Drizzle at Temperatures Below −25 °C Observed at McMurdo Station, Antarctica, Journal of Geophysical Research: Atmospheres (2019).
« Last Edit: November 07, 2019, 05:58:21 PM by vox_mundi »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late