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Messages - D-Penguin

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1
Arctic sea ice / Re: The 2020/2021 freezing season
« on: September 19, 2020, 08:02:38 PM »
Animation of the annual max and min, from 1979 to present (click to play).

2
Arctic sea ice / Re: The 2020 melting season
« on: August 31, 2020, 11:01:56 PM »
NSIDC 14-day sea ice extent reduction (due to melting and sea ice floe pulverisation) has been -64,000km2 per day if 85,000 km2 solitary 28.8. spreading event is eliminated from the series. Lesser scattering events may occur but these then will lead to further fragmenting below the 15% threshold.

There is heat in the ocean to melt the ice, but the buoy temperatures steadily fall. Barring major storm events it is near flat bottom of the melting curve for 2020. More questionable is Russian coasts where is more heat to dissipate to delay the refreeze. On the Atlantic Side, melting advances for weeks incrementally but is fully compensated in cooling air over the Central Arctic and North Pole forming ice.

I expect, nevertheless, rapid sea ice re-growth to occur facilitated by the widespread ice floes in Arctic.

More worrying is near Blue Ocean event next year and its forecast effect on the jet stream-driven rain belts moving in GCMs from a line north of the British Isles to the median around the Strait of Gibraltar, with the winter rain belts shifted to Morocco, Spain, Portugal, and Southern France, with the Beasts of the East, easterlies originating from Siberia brining very crispy air over Northern and Central Europe. The median occurrence in the models point to post-2021-melt circulatory change peaking by year end.

For general public 1,000,000 km2 BOE will appear cheating by experts and I would not market the event as such until the ocean is genuinely ice free (which I think is also just behind the corner as the last remaining ice bits to vanish take increasingly less energy due to diminished volume).

We need to readily assault against false climate change denialists' claims as surely they will come to haunt us 2021 if we claim blue ocean when there is million square kilometres of ice still left behind.

The surest sign of the final arrival of the Blue Ocean is when the Russian and American submariners are hugging in each other's arm pits under the very last ice floe - somewhere north of Canada.  :P

3
Arctic sea ice / Re: 2020 Sea ice area and extent data
« on: August 29, 2020, 02:27:32 PM »
NSIDC Daily Area: August 28

Arctic Sea ice area: 2,747,785 million km^2.

Change from yesterday: Area gain of 58,132 km^2

(2020) NSIDC: Area daily: 2.747               NSIDC: Extent daily: 4.448


NSIDC: September daily area minimum     NSIDC: September daily extent minimum

(2012) 2.241                                             : 3.340  <<  Sep  16
(2016) 2.477                                             : 4.145         Sep   7               
(2011) 2.940                                             : 4.333         Sep   8
(2019) 2.960                                             : 4.166         Sep 17
(2017) 3.020                                             : 4.635         Sep 13
(2007) 3.050                                             : 4.155         Sep 18
(2008) 3.120                                             : 4.586         Sep 19
(2015) 3.160                                             : 4.387         Sep   8
(2018) 3.270                                             : 4.630         Sep 21

4
Arctic sea ice / Re: MOSAiC news
« on: August 29, 2020, 01:55:22 AM »
Quote
A bit late, posted on aug17. Collecting buoys etc in the Fram strait
So once again, a bogus caption on a photo? They were not anywhere near the Pole on the 17th. Nor were they in the Fram but rather 86.8 12.3. Even the cheapest flip phone records time of photo on the photo.

AWI does provide a photo database for media but access requires a login that does not recognize the account you just created.  Sound familiar? https://multimedia.awi.de/medien/earlylogin.jspx
Quote
Jet stream important influence?
Of course in the big picture it's all tied together, though to date we appear no closer to reliable 5-day much less seasonal predictions than ever. Knowledge of the jet stream does not lead useful prediction of the surface winds that actually physically couple with the ice,.Especially this August, that would be a big leap given the jet stream's complex and semi-chaotic structure.

Rain, fog, melt pond and snow distribution: terribly important to the ice but where in the jet stream graphic (or any satellite product 42 years in) do I find reliable data for them at the scale we need? We have to get some better sensors out there; the Polarstern is not the answer.

Consequently, I would rather glance at nullschool 1000 hPa winds twice a day rather than read ungrounded weather speculation on the melt forum. And that is true too where I live, despite a full-time gov't Wx staff of seven, they cannot get a half day ahead on weather specifics such as rainfall.

So yes, maybe we can usefully do 2-3 days forward but really after-the-fact (yesterday) is the best option, if it is not a broad-brush climate forum. But frankly, given the importance of Arctic sea ice to the global climate system, the complete ignorance demonstrated on Aug 19th of the state of the north pole regional ice makes me wonder what they've been putting in the models all these years in place of observational fact. Having half the ice pack in melt pond doesn't matter?

But even with weather facts in hand, the explanation can elude us. Search 'arctic amplification' at google scholar. The top hit is a 2006 paper by MC Serreze and JA Francis called "The Arctic Amplification Debate". They could write a second paper with that same exact title today. The phenomenon has been under debate since 1969.

https://en.wikipedia.org/wiki/Polar_amplification#History

5
Arctic sea ice / Re: MOSAiC news
« on: August 27, 2020, 05:43:04 PM »
The pace and style of old academia, as done by the Polarstern scientists is failing us. By the time they get their results published those results will be out of date. Yes, the basic science has not changed, but the ice conditions have deteriorated over the past 3 years.

We are mostly flying blind on this forum, speculating or measuring insignificant changes to infinitesimally diminishing significance.

I plead guilty to speculating about what's happening below the ice between Greenland and the pole. The key factor was probably the unprecedented clear weather and direct sunlight, but we need buoys down there recording what's happening and we need real time analysis by knowledgeable scientists like A-Team. I agree with him about the deployment of surface and below surface instruments. Satellite measurements have limited capabilities as we can see with our own eyes from the photos at the pole.

The Arctic is melting rapidly while the traditional scientists play their old academic games. And the atmospheric circulation is shifting all the way up to the upper stratosphere while they dither over which ice floe to moor on. (The rapid jump in the QBO this summer is very unsettling.)
https://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/index.html

Thanks A-Team for your analysis.

6
Arctic sea ice / Re: The 2020 melting season
« on: August 23, 2020, 12:51:28 PM »
Updated version (improved colour scheme) of the comparison between the extent and concentration changes for the first 3 weeks of August.

7
Arctic sea ice / Re: The 2020 melting season
« on: August 22, 2020, 10:24:42 PM »
First 3 weeks of August.

8
Arctic sea ice / Re: The 2020 melting season
« on: August 21, 2020, 04:56:16 PM »

Interesting Thickness normally goes up at this time of season it was rising then took a large drop down.
Usually I am read only here. However, this one rises a question. Looking at the avg. thickness, would it be possible to see a stall or even drop in extend/area in early November with increased bottom melt?

9
Arctic sea ice / Re: The 2020 melting season
« on: August 13, 2020, 10:14:54 AM »
Here's another for ye.

10
Arctic sea ice / Re: Freeform season chatter and light commentary
« on: August 12, 2020, 09:00:48 PM »
Wdmn, the phase change itself needs energy.
Link >> http://hydrogen.physik.uni-wuppertal.de/hyperphysics/hyperphysics/hbase/thermo/phase.html

     Sorry, no facts to add to the question, but here some perspectives for those of us who don't work with ice physics every day. 

      It always shocks me when reminded that the heat exchange between frozen vs. melted ice is 80% of the heat energy change required to change water temperature from 0C to 100C.

      That huge energy budget to melt ice has been a defense mechanism for preserving the Arctic sea ice.  Consider the 75+% ice volume losses since 1979, the amount of heat input that required is huge.  As the Arctic loses that defensive wall (the ice phase transition energy requirement), the continued energy input into a decreasing portion of ice and an increasing portion of open water means that things will soon be getting even stranger even faster.

      All of us on ASIF are interested in seeing the volume minimum this year.  We don't get daily updates and images for volume like we do for extent and area, so volume gets a lot less discussion.  But it really is the key number (with a respectful nod to Area as the factor that directly affects albedo).   The 2020 minimum volume will almost certainly be closer to the 2012 record low than either extent or area.

       Thickness is also difficult to measure and visualize.  But it also deserves more respect.  Lots of discussion recently about slow down in extent and area trends, with simultaneous comments about how terrible the ice looks.  It is too bad we don't have regular reports and images about qualitative measures of ice condition like thickness, mechanical strength, continuity etc. Concentration is a qualitative measure of ice pack condition, but it is highly variable and apparently is difficult to accurately measure because of sensor errors caused by water on the ice surface and water vapor in the air.

       One of the key things I've learned this year is to mentally blur the dark areas on the much appreciated and repeatedly viewed AMSR2, U. Bremen, U. Hamburg, and Hycom animations posted by ArticMelt, Blumenkraft, Born from the Void, and others.  I think it was a great idea somebody had on the 2020 Melt Season thread to create  5-day average values for such images as a way to smudge some of the spurious readings and highlight what are the more likely true indications of low-concentration and softening ice

       The 2020 story seems to continue the narrative from 2019  -- continued decline but no replacement of the 2012 record-low quantitative measurements, with progressive rot in the qualitative impressions of ice condition.  Continuation of that trend leads to a point where ice thickness and qualitative melt resistance, exacerbated by increased forces of albedo, ice mobility, fracturing (and thus surface area and lateral melt by contact with ocean water as noted by JD Allen) reach a tipping point at which the right conditions create a major "Poof Event" where huge number of extent and area km2 disappear in a short time period. 

       The math backs up this theoretical scenario.  At some point the flatter Extent decline curve has to catchup to the steeper Volume decline curve.  The closer to the end point at which that occurs, the more radically steep the change in Extnet curve has to be.  I thought that Exent would begin that catch up process by now, but I've been wrong about that so far.  Thickness going below 1 meter could be a key tipping point for that Extent decline acceleration to occur.  We are very close to reaching that tipping point. 
       
       Of course, it isn't a smooth incremental process.  What happens in the real world depends on the chaotic vagaries of the weather.  And the early 2020 melt season seems to have been a doozy among those vagaries.  The rot evident in the former MYI bastion of the Ellesmere - Greenland - North Pole triangle is notable as both a qualitative and quantitative highlight of 2020 so far.   

       In earlier years, for a total melt season to reach "Poof Event" intensity would have required prolonged, extreme and unusual conditions.  But with each year of progressive qualitative decline (i.e. ice pack rot), the conditions required for a severe melting event to occur become less extreme and less far beyond the normal range, and thus more likely to occur.  That is exacerbated by the fact that as the Arctic continues to warm, the "normal range" for the amount of energy in melting events increases, thus making the required intensity for a catastrophic "Poof Event" even more likely to occur.

      As for 2020, it ain't over til the fat lady sings.  The amount of low-resistance ice hovering just over the 15% concentration threshold to be counted as a 100% extent pixel could still result in some dramatic drop days.  IMHO, those values, while interesting to watch, are the daily news that is more noise than signal.  The signal is the qualitative decline in ASI overall and the increasingly dire setup for a knockout punch. 

      I didn't mean for this reply to get so long.  Oren, if this is the wrong thread for a sermon, please relocate as needed.  Here is some more positive news - Tesla Inc.'s Battery Day, scheduled for Sept. 22, could bring big news to help us dig out of this mess.  Getting back to doom and gloom, it will be interesting to see what adjectives Friv has saved up for the first big Poof Event.

11
Arctic sea ice / Re: The 2020 melting season
« on: August 08, 2020, 11:16:57 AM »
First week of August, 2012 vs 2020
(Higher-res version on twitter: https://twitter.com/Icy_Samuel/status/1292026425348886529)

12
Arctic sea ice / Re: The 2020 melting season
« on: August 07, 2020, 10:32:13 PM »
An animation of the simple projections so far this melt season.

13
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 09:51:08 PM »
Here's the video (gif was waaaay too big) of the concentration and MODIS data side by side for July. Let me know if there's any suggestions on improving it.

(Edit: Removed the video - didn't realise it was autoplaying. Here's a link instead:https://twitter.com/Icy_Samuel/status/1289672698361257984)

14
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 08:27:15 PM »
A lot changes in a week. A week ago a record year looked very possible but now the slowdown and dispersion have made a top 3 place seem likely. Even the thin ice takes a while to melt and as nights get darker peak melting has passed now.

Still a lot of things happened in the Arctic in 2020 that never happened before so 2030 free of sea ice in Summer is very possible.

Every year the Arctic makes us think it is all going to melt out only to surprise us in another way. Slowdown is well under way now but there will be further big drops bringing final Jaxa extent to just under 4m like 2019 but let's wait and see.


Let me tell you, the spring is loading and soon you'll see around century drops again. Don't jump on every cliff or slow down but try to keep the bigger picture in view.

15
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 10:05:47 AM »
In physical reality, what matters most is thickness distribution (and volume), then area, then extent. If the ice is driven in a compacting transport, extent will plummet with not much physical impact, while the reverse is also true under a divergence regime. What we can see unfortunately with the satellites and models is the opposite, extent in high accuracy, area in medium accuracy, thickness distribution and volume with low accuracy and delays.
This allows both parties to have numbers and data on their side, which is fine, just has to be interpreted according to physics and not just visible numbers on a chart.
The sunny July did huge damage to the CAB in terms of volume, and the open Siberian seas are a disaster waiting for imports, while the Atlantic front has huge amounts of open water as in 2012 and 2016, very unlike 2019. OTOH the Beaufort is full of ice and the CAA and Greenland Sea are still holding up. The question we do not know is how much of the remaining ice is in marginal conditions - still whole for now but will melt out by mid-Sept. This is what will dictate the area numbers, and partially the volume numbers as well, as volume calculation is tied to measured area changes. The extent numbers will be dictated by area numbers, but very highly affected by compaction or divergence - very visible, much less important IMHO. 2016 was almost as low as 2012 in terms of area, but very high up in terms of extent.
My take on things is that the ice is thinner than appears, due to the impact of July insolation and due to very high movements in the last few weeks, which induced faster bottom melt. I have never seen so many days where the CAB was entirely visible, and this while the ice was doing a crazy dance around the basin. Then came the cyclone with movements induced in the other direction. The CAA has been sweltering in heat and the ice is all broken up. So I expect a some point a lot of the ice which originated with a standard FYI thickness will melt out, and so will some of the thinner MYI. This will probably leave us with a total area record or near-record, even though the Beaufort may not be in record territory at all. Oh yeah, I also expect a volume record. I can't say the same for extent, which might be far away from 2012's record, though surely below 2019. This depends on random September factors so can beat the seasoned forecasters easily.
August is upon us, the answers will be clear in a few weeks time, not much longer to wait.

16
Arctic sea ice / Re: The 2020 melting season
« on: August 01, 2020, 05:49:15 AM »
A lot changes in a week. A week ago a record year looked very possible but now the slowdown and dispersion have made a top 3 place seem likely. Even the thin ice takes a while to melt and as nights get darker peak melting has passed now.

Still a lot of things happened in the Arctic in 2020 that never happened before so 2030 free of sea ice in Summer is very possible.

Every year the Arctic makes us think it is all going to melt out only to surprise us in another way. Slowdown is well under way now but there will be further big drops bringing final Jaxa extent to just under 4m like 2019 but let's wait and see.

I was just thinking, "there are still 6 or 7 weeks left of melting, wonder how excited people can get based on one week of anticyclonic dispersion". Then I read the beginning of your comment, and thought, "here we go!" - but then I read the rest and was majorally mollified.

One week ago I escaped from a three-week Internet blackout only to see that I'd completely missed out on the July hammering. A new minimin seemed to be the generally accepted version of the future, anybody predicting anything else was quickly hammered down. Then a few days of blow from a short-lived cyclone and the previously repressed prognasticators rise to the surface, while even Friv seems to have lost steam.

I guess it is all part of the rich tapestry that is life. My two cents worth is that we will land in the middle of the fourth million, with a slim but real change of a new minimin. But what do I know?

17
Arctic sea ice / Re: Freeform season chatter and light commentary
« on: August 01, 2020, 03:43:35 AM »
Swiss cheese is made with two strains of cheese bacteria so the parable is excellent, swiss cheese bacteria act as plumes of hotter water... --> tries to go on to parable other types of cheeses to other types of ice. White mould cheese with the crust - multiyear ice, blue cheese- leads and pressure ridges. Gorgonzola - stacking ice slabs, peppered cheese, soft cheese...

Thanks. :)


18
Arctic sea ice / Re: The 2020 melting season
« on: July 31, 2020, 08:12:30 AM »
An update on the side by side comparison. Those apparent concentration drops are looking more real than not.
Slightly higher res version on twitter, for those without data limits: https://twitter.com/Icy_Samuel/status/1289080922617372672

(Large file, click to play)

19
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 07:12:26 PM »
Latest Five Day Forecast
Wind @ Surface + Total Precipitable Water
Large GiF!

20
Arctic sea ice / Re: The 2020 melting season
« on: July 30, 2020, 05:54:12 PM »
Some of the concentration reductions are very real, some aren't. How much is real won't be apparent until we get more clear views.
Por ejemplo...

21
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 12:53:47 PM »

There is a mistake with the left image. It's labeled 2012.

Nice catch, fixed!

22
Arctic sea ice / Re: The 2020 melting season
« on: July 28, 2020, 11:49:26 AM »
Concentration for the 26th, 27th and both combined.

23
Arctic sea ice / Re: The 2020 melting season
« on: July 27, 2020, 03:43:53 PM »
Side by side of July 26th in 2012 and 2020.

24
Arctic sea ice / Re: The 2020 melting season
« on: July 24, 2020, 11:32:07 AM »
The Beaufort is high extent because temps have been normal.
I don't think that's the only reason Friv. I think a slowdown of the gyre and thicker ice may have something to do with this as well. And then I saw the low sality...

But as you all know by now, I'm just a fat guy with a computer, so I'm gonna shut up now and leave it up to the specialists.  :-X
It certainly is not the reason. Clickon this animation of the last ten days of the furious pace of discharge from the central arctic sea into the Beaufort, both down the CAA coast, and also clearly visible the motion towards the Chukchi of the fragmented and low concentration central Beaufort.
The Irminger current historically used to turn south below Greenland and dip around Greenland before merging with the Labrador and heading south.
As pictured. Last ten years Its been turning south further north near Svalbard. Now last year, and even more this it has decided to go over the top of Greenland, and this year, not even satisfied by colonising the CAA, and Aided by the Beaufort clockwise gyre being closer to Mckenzie Bay,  it has stopped the Alaskan coastal current, heading east from Bering,  or at least pushed it under to flood the central Beaufort.
As you are seeing some is also going along the siberian coast.
It should be no surprise with this going on that the Beaufort, Chukchi and north of Greenland are about to catastrophically crash, along with the CAA. Particularly if the sub 980 low forecast in the Beaufort appears in a few days as forecast.
Click on Hycom thickness and concentration animations to see whats been and about to happen.

25
Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: July 19, 2020, 06:42:30 PM »
...
IMO the individual studies are interesting and sometimes brilliant but of very limited value because they lack the component that provides the 'intuitive leap' that gives 'usefulness' to the study. In the case of an 'Ice Apocalypse', a more rationalized and realistic time-frame.

...

Regarding consensus climate science repeated reference to ice sheets losing ice over periods of centuries or millennia, I note that what most people think of as 'the science' is limited to Frequentist (as opposed to Bayesian) interpretation of the scientific method.  A Frequentist interpretation requires the establishment of experiments that simulate all key considerations, run a sufficient number of times to generate statistics that the Frequentists use as probabilities for possible future events.  To generate climate change statistics Frequentists primarily look at: a) the paleoclimate-record; b) the observed climate record and c) climate model projections.  Unfortunately, our current Anthropocene Period has no direct parallel in the paleoclimate record; and the observed record is too short to say much about long-tail climate risks and current climate models (including CMIP6 models) are not yet sufficiently sophisticated to simulate nonlinear extreme/abrupt climate behavior.

Therefore, when Frequentist/consensus climate scientists look at the paleoclimate record they average-out possible MICI-types of event citing poor resolution of the paleo-record and then focus on the slower trends of ice sheet ice mass loss; and when they look at the observed record they only see limited ice cliff failures for individual glaciers (like Jakobshavn) but no MICI-type events and when they look at model results like those of DeConto & Pollard (2016) or James Hansen et al (2016) they discount these preliminary findings as these models depend on some human judgement (which is commonly used in Bayesian methodologies).  Thus if abrupt freshwater hosing events do occur in the coming decades they will likely catch the Frequentist/consensus climate scientists by surprise and they will say that such abrupt behavior reflect 'Black Swan' events that could not be projected, even thou numerous warnings have been made public by the likes of James Hansen, DeConto and Pollard.  At the end of the day, many decision makers like to shirk responsibility for using human judgement and until they start choosing to shoulder responsibility the consensus climate scientists who report to these decision makers will continue to discount long-tail risks and will caveat their incomplete Frequentist statistics (that they present as true probabilities) with small print footnotes that ease their collective guilty consciousness over not presenting the actual risks associated with 'Ice Apocalypse' scenarios.

26
Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: July 19, 2020, 05:02:46 PM »
ShortBrutishNasty was thoughtful enough to send a link to me about James Hansen's latest article about paleo, and model, evidence about slowing of the MOC during periods of high GMSTA, see below:

Title: "Every Rock Has a Story & The Rock Whisperer" by James Hansen July 17, 2020

http://www.columbia.edu/~jeh1/mailings/2020/20200717_RockStories.pdf

Extract: "Curiously, at almost exactly the same moment that I received an e-mail from Ethan Baxter, I received one from the Rock Whisperer, my friend Paul Hearty, with a copy of his current paper on rocks in South Africa. He and co-authors show that in the Mid-Pliocene (about 3 million years ago), when atmospheric CO2 was about the same as today, it was a few degrees warmer and sea level was 15-30 meters higher (50-100 feet). One of Paul’s co-authors is Maureen Raymo, the new Director of Columbia’s Lamont-Doherty Earth Observatory, who dubbed Paul the Rock Whisperer for his remarkable ability to read the story in the rocks.

In 2006, when I was concerned that the IPCC projections of sea level rise were unrealistically conservative, I suspected that something was wrong with the ocean models that IPCC relied on. For one thing, the models did not properly include the cooling effect of ice melt on the North Atlantic and Southern Oceans. So, we ran climate simulations with our coarse-resolution global model, and were startled by the result: we found that the world was on the verge of shutting down both the Southern Ocean and North Atlantic overturning circulations, with enormous potential consequences for future sea level, because of amplifying feedbacks for Antarctic ice.

This would be a hard story to sell, given the coarse resolution of our model, and the fact that our result seemed to differ from all the other models. And why did Earth’s history not reveal such rapid feedback-driven change in the past? That’s when I discovered the papers of Paul Hearty for the last interglacial period, the Eemian, about 120,000 years ago, when global temperature reached levels perhaps as much as 1-2°C warmer than the preindustrial (1880-1920) level.

Hearty’s reading of the rocks painted a picture of the Eemian that was consistent with what we were finding in our climate modeling. We needed to develop that story, so we started to work with Paul Hearty, but first we needed an explanation for what was wrong with the ocean models.

The most crucial information about the ocean models was provided by observations of heat uptake by the oceans. Here the expert, the ocean heat whisperer if there is such a thing, was a young post-doc, Karina von Schuckmann, with whom we began to collaborate in about 2010."

Hearty, P. J., Rovere, A., Sandstrom, M. R., O'Leary, M. J., Roberts, D., & Raymo, M. E. (2020). Pliocene‐Pleistocene stratigraphy and sea‐level estimates, Republic of South Africa with implications for a 400 ppmv CO2 world. Paleoceanography and Paleoclimatology, 35, e2019PA003835. https://doi.org/10.1029/2019PA003835

https://www.essoar.org/doi/10.1002/essoar.10503699.1

Abstract: "The Mid-Pliocene Warm Period (MPWP, 2.9 to 3.3 Ma), along with older Pliocene (3.2 to 5.3 Ma) records, offers potential past analogues for our 400-ppmv world. The coastal geology of western and southern coasts of the Republic of South Africa expose an abundance of marine deposits of Pliocene and Pleistocene age. In this study, we report differential GPS elevations, detailed stratigraphic descriptions, standardized interpretations, and dating of relative sea-level indicators measured across ~700 km from the western and southern coasts of the Cape Provinces. Wave abrasion surfaces on bedrock, intertidal sedimentary structures, and in situ marine invertebrates including oysters and barnacles provide precise indicators of past sea levels. Multiple sea-level highstands imprinted at different elevations along South African coastlines were identified. Zone I sites average +32 ± 5 m (6 sites). A lower topographic Zone II of sea stands were measured at several sites around +17 ± 5 m. Middle and late Pleistocene sites are included in Zone III. Shoreline chronologies using 87Sr/86Sr ages on shells from these zones yield ages from Zone I at 4.6 and 3.0 Ma, and Zone II at 1.04 Ma. Our results show that polar ice sheets during the Plio-Pleistocene were dynamic and subject to significant melting under modestly warmer global temperatures. These processes occurred during a period when CO2 concentrations were comparable to our current and rapidly rising values above 400 ppmv."

27
Antarctica / Re: Ice Apocalypse - MULTIPLE METERS SEA LEVEL RISE
« on: July 19, 2020, 04:46:00 PM »
...
A very fair point and good example of where the science has joined some of the 'dots' for the purpose of informing the decision makers.
...

D-Penguin,

I have made more posts critiquing consensus climate science projections than anyone else on this forum so I certainly share many of your reservations about 'the science' and/or 'consensus science'.  The fact of the matter is that the world is a much more complicated place than any Earth System Model, ESM, can replicate; therefore, projections from 'the science' can only represent a part of reality, and the parts left unmodeled represent uncertainty (or deep uncertainty); which decision makers can either use to try to ignore consensus science projections (such as the Trump Administration) or they can shoulder responsibility for the uncertainties and evaluate risks (probability times impact) associated with a range of possible scenarios (using the Precautionary Principle) ranging from mild to extreme.

As consensus climate science has a proven bias to err on the side of least drama; I try to use published (peer reviewed) scientific reports (consensus or otherwise) as a starting point and then I try to discuss many of the considerations that they have omitted from their models due to uncertainty/ignorance and/or lack of computational power (note that E3SMv4 will use exascale computers to partially address this short-coming).  For example, in an earlier post that you commented on, I cited the risk of cascading freshwater-hosing-related tipping points accelerated by the bipolar seesaw mechanism, so here I elaborate a little bit on what such an extreme scenario could build on the projections of E3SMv1 presented in CMIP6:

1. E3SMv1 projections indicate that glacial (including ice shelf) ice melting from both the GIS and the AIS is currently contributing to a slow-down of the MOC and that MISI-types of calving will accelerate this slow-down in coming decade, resulting in a relatively high value for TCR of about 2.93C for the rest of this century.  However, this projection ignores both MICI-types of mechanisms and a cascade of freshwater hosing events modulated by the bipolar seesaw mechanism via both atmospheric and oceanic telecommunication mechanism.

2. In my opinion there is a reasonable chance that the current slow-down of the AMOC (which is increasing the ocean heat content particularly in both the Southern Ocean and the North Atlantic Ocean, see the first attached image) will serve to increase the frequency and magnitude of periodic warm ocean water fluxes into the fjords of key marine terminating glaciers in Greenland (and also in Antarctica) so (in my opinion) that in the 2025 to 2030 timeframe that there will be a 5-year long surge of (ice cliff related) accelerated calving events from such key marine terminating glaciers as: Jakobshavn, Petermann, Zachariae, etc. that would both accelerate the slow-down of the MOC (thus warming the SST in the Tropical Pacific which would then atmospherically telecommunicate additional heat to the WAIS) and would contribute to a small increase in sea level in coastal West Antarctica.

3.  The result of the freshwater hosing event cited in item 2 would serve to help destabilize the marine glaciers in the Amundsen Sea Embayment, ASE; which together with a likely Super El Nino event and a likely subglacial lake drainage event beneath Thwaites, in the 2030-2035 timeframe; might likely both cause the PIIS to collapse and cause the Thwaites Glacier to undergo an MICI-type of collapse of the entire Byrd Subglacial Basin (BSB) by 2035.  Such a freshwater hosing event would not only further slow the MOC [by slowing AABW formation, around Antarctica, see Nakayama et al (2020)]; but would also slight rise sea level around Greenland and would push relatively warm Pacific water through the Bering Strait into the Beaufort Sea (see the second attached image from NOAA 2017).

3. The warm Pacific water intruding into the Beaufort Sea by 2035 cited in item 3 would likely trigger an abrupt release of freshwater from the Beaufort Gyre into first the Arctic Ocean (where it would destabilize the halocline resulting in abrupt melting of the Arctic Sea Ice) and then into the North Atlantic, where it would likely contribute to an abrupt slow-down of the AMOC, possibly in the 2035 to 2040 timeframe; which by the bipolar seesaw mechanism could trigger the abrupt collapse of both the FRIS and the RIS in the 2040 to 2045 timeframe that could contribute to the collapse of the vast majority of the remaining WAIS within the 2045 to 2090 time frame.


Nakayama, Y., Timmermann, R., and H. Hellmer, H.: Impact of West Antarctic ice shelf melting on Southern Ocean hydrography, The Cryosphere, 14, 2205–2216, https://doi.org/10.5194/tc-14-2205-2020, 2020.

https://tc.copernicus.org/articles/14/2205/2020/

Abstract
Previous studies show accelerations of West Antarctic glaciers, implying that basal melt rates of these glaciers were previously small and increased in the middle of the 20th century. This enhanced melting is a likely source of the observed Ross Sea (RS) freshening, but its long-term impact on the Southern Ocean hydrography has not been well investigated. Here, we conduct coupled sea ice–ice shelf–ocean simulations with different levels of ice shelf melting from West Antarctic glaciers. Freshening of RS shelf and bottom water is simulated with enhanced West Antarctic ice shelf melting, while no significant changes in shelf water properties are simulated when West Antarctic ice shelf melting is small. We further show that the freshening caused by glacial meltwater from ice shelves in the Amundsen and Bellingshausen seas can propagate further downstream along the East Antarctic coast into the Weddell Sea. The freshening signal propagates onto the RS continental shelf within a year of model simulation, while it takes roughly 5–10 and 10–15 years to propagate into the region off Cape Darnley and into the Weddell Sea, respectively. This advection of freshening modulates the shelf water properties and possibly impacts the production of Antarctic Bottom Water if the enhanced melting of West Antarctic ice shelves continues for a longer period.

Edit: Obviously, this cascade of freshwater-hosing-event-related tipping points modulated by bipolar seesaw mechanisms would likely continue beyond 2090 (and would likely trigger other positive feedback mechanisms prior to 2090); such as:

a) an increase in the frequency and intensity of both El Nino events (promoting more surface melting events in West Antarctica) and of Atmospheric River events impacting Greenland (promoting more surface melting events) both of which should increase hydrofracking of ice cliffs and of ice shelves.

b) Activation of MICI-type of behavior in key EAIS marine glaciers like Totten, and Byrd, possibly as early as 2060 to 2070.


28
Arctic sea ice / Re: The 2020 melting season
« on: July 16, 2020, 03:25:13 AM »
Its very likely that we will see cyclogenesis over the arctic basin at some point during the last part of July or early August.

There are powerful  ingredients aligning  that can come together and cause a major BOMBOGENESIS event over the arctic basin.

While having a stark contrast of cold ice next to relatively warm water next to relatively warm land can aid in cyclogenesis, moisture transport, low level lift from warm moist air(relative) going perpendicular into the cold low levels over the ice.  Most of the time there is a low level atmospheric cap in place over the ice between 850-950mb since three warm mid  level air sits on top of the natural atmospheric refrigerator which is the floating ice sheet. 

But sometimes when the large ANTICYCLONE is starting to break down colder air can become displaced back over the ice while a separate surge of warm moist air  that originates in the mid latitudes is brought into the basin by the previous now dying flow between the ANTICYCLONE and unorganized vortex. 

This can lead to a low level flow between 800mb and 950mb with  air  penetrating the arctic ocean that's 10C(800mb) to near 20C(950mb).

If things align just right you can get a warm pulse from NW territory or Siberia that comes right off the land early in the day and punches straight into the cold pool.  Timing is crucial because diurnal heating can bring a near surface(1000 feet and down)  bubble of air that warms up into the 25-33C range as it quickly rises and gets turbo charged towards the ice by the low level jet. 

Of course this moist warm air will start cooling.   

However this air will already be lifting off the ground by the time it starts intersecting the established cold pool.  The air will be well off the ground rising while caught in the low level jet.

This ermac will continue to rise as it intersects the cold bubble sitting over the ice.  you can imagine even though this air will be modifying as it lifts into the mid levels over the ice that the temperature and moisture gradient is tremendous having that kind of heat rise over the cold air.

This will help initiate tremendous lift.  And if there's already vorticity in the area intersecting this.

Things will f****** pop off.  The Arctic is kind of special because the jet stream can meander and intersects itself not only in a dual position but a tri position.

Over the Eastern continental United States and Canada.  We see storm systems merge all the time but sometimes the tropical jet meats the southern branch of the polar jet which may have broken in the two as it reached the western coast of North America.  So all three jets meet each other over the eastern part of North America all bringing with it moisture and atmospheric VORTICITY.

With the southern jet bringing tropical moisture feed into this trifecta. 

We call it a triple point phase.  This is how the March 1993 superstorm formed. 

these conditions in the arctic while not having near the amount of heat and moisture the subtropics can provide even in winter can come together rather easily because of the small area that is the top of the Earth.

it seems to me that the main limiting factor in terms of bringing deep moisture into the Arctic is heat displacement.  The Sun is never going to be strong enough to bring tropical conditions or even mid latitude conditions.

Even if there was opening water between 60 and 70 North straight from jump in May during the melt season.  even if that area just happened to have a major ridge high practice it over it for May and June with mostly sunny skies 90% of the time the amount of heat that would be collected into that area of water would still be very limited.  While the surface theoretically to warm to say 15 maybe even 20 degrees Celsius.   The depth at which that heat would accumulate would be very shallow. 

This is something that could only really be overcome by very warm water coming in from the South.

This is where an area like the Barents can change from a sub Arctic ocean to a mid latitude ocean permenantely once the level of heat in the warm water conveyor belt is consistently warm enough to overcome the natural cooling from the solar minimum.

At some point once the warm water current is ready for the transformation of the barents.  We will likely need to see a spring to Summer event where a large ridge of high pressure sits in the right position over the barents long enough to add a level of heat through depth that matches the heat in the current so that new ocean currents become established that allow the warm conveyor belt to press further north instead of being submerged. 

Once this new normal is established the natural cooling from the solar minimum may not be enough to overcome the new normal and stunt the warm conveyor belt back to previous norms.


This taking place would be a game changer because you would have the cold Arctic and sea ice always forming along the losomov(mis spell) valley around the 81-83° latitude range.

So there would be ice there every Spring and early summer.  Even tho right next to the ice and cold pool a warm Barents sea in late Spring and Summer will exist harboring 10-20C water temps even through depth.

Imagine powerful mid level cyclones forming in August-November and tracking along the boundary between the barents and deep cold Arctic ocean.

Imagine a massive polar vortex breaking off the ENA area and migrating down that path.  Tapping into those 10-15C SSTs in November or December.

That polar vortex would aquire a warm pool and could under go extreme cyclogenesis.  Not always as a small compact system but a major mid latitude cyclone displaced North that has a deep warm moist sector of 10-15C SSTs and deep cold air ranging -20 to -30C.  While these airmasses collide around Svalbard.

And an unprecedented extreme cases this system would intersect a powerful piece of VORTICITY in the polar jet.

The result could be storms at depth, size, and power we have never seen as humans.

Trying to push sub 900mb.

Bringing 75-115KT sustainable winds over huge parts of the Arctic.

Bringing massive swells and waves along a 2000 mile fetch slamming INTO Atlantic side ice.

Anyways I have ranted to long.

29
Arctic sea ice / Re: The 2020 melting season
« on: July 15, 2020, 06:28:55 AM »
I think this is strongly related to what is happening in the Laptev and ESS this year (and the record-breaking heat YTD in Northern Siberia). We have seen a signal for a snowier Himalayas in recent years however we have been unable to verify whether it is noise or actually accurate, as many of the websites whose data we use for SWE / extent is not accessible beyond what we have recorded here on ASIF. There has been much speculation that I certainly agreed with that the Himalayan data may have been wrong or incorrect.

I took a look at June-July (to date -- 6/1-7/12) temp anomalies since and including 2010. One of these years is not like the others across Eurasia, in fact, the temperature anomalies in the Himalayas this year are downright frigid and ranging up to 8C below normal in peak summertime -- I can't imagine that is doing wonders for snow levels, and I would also imagine all that extra remaining +SWE in the highest altitudes of the Plateau / ranges is helping to seed the worsening summer rainfall event over Western China as incoming airmasses move overtop the mountains.

At the same time as the increased precipitation in this region is driving more year-round depth and extent in the Himalayas this year, it is having another major impact. I would wager the excess albedo at such low latitudes is having a profound impact on polar heat transport and is likely to dramatically accelerate the process. Such widespread temperature departures comport to negative -500MB anomalies which basically means there is an increasingly less temporary area of polar vorticity atop the Himalayas now gaining relative strength to the primary gyre in the Arctic.

As we see more heat accumulate in the Indian Ocean and this is transported northwards, more snows fall in the high Himalayas, dragging down the snow line, and INCREASING the efficiency of the heat transport as we head deeper into the year. Basically, as we see more snow linger in high elevations and low latitudes, the enhanced baroclinic gradient is going to send more and more of the surrounding continental and oceanic heat (ever-more amplified by our ever-rising GHGs) northward into the primary polar cell, ultimately destroying it earlier and earlier each and every year. The other anomalous patches of continental snowfall in North America are having the same impact, IMO, and while the impact shifts regionally year over year it is now seemingly WORSENING as a whole which is becoming a driving contributor to Arctic amplification. 

For the time of year, Eurasian SWE is apparently now a month behind normal... which comports very well with the anomaly map. While 200KM^3 of volume may not sound like a lot, when it is distributed atop the mid/low-latitudes at peak insolation.... that is a lot of disparity now relative to the old regime, especially with all the albedo loss in the Arctic! (PS, the +200KM^3 of volume is apparently worth about a million extra KM^2 in area!)

Also -- oren -- please feel free to move this to "snowfall" but I felt this was very relevant and a definite cause of our predicament in the High Arctic this year / will be a major contributing factor in warming up north moving forward.

PPS: July to date in particular has been.... surprisingly frigid (???)... in Arctic-adjacent Siberia. A whole lot of good that cold is doing for the ice....

<I will let it stay this time, but normally such long discussions which are mostly about something else would best be served in a more relevant thread, in this case the "snow" thread. O>

30
Arctic sea ice / Re: The 2019/2020 freezing season
« on: November 10, 2019, 07:34:11 AM »
I have spent many years lurking on this forum. Over the years I see little to give me hope that climate change will not devastate the Arctic and the planet as a whole.

I teach climate change in my classes at a community college in Southern California. In my feeble attempt to explain how these great dips of the jet stream that bring an Arctic blast to the eastern half of the USA can hurt the Arctic I use a freezer we have in the classroom. I open it up to let the cold out and ask them “When I close the door, how does the freezer make it cold again?” I tell them about condensers and heat exchangers.

 I ask them “How does the Arctic keep so cold when its freezer door is opening when the jet streams make these large dips?” My feeble answer is we have a season of dark in the Arctic that is the time when we generate all the cold in the Arctic freezer by a lack of energy input directly from the Sun. Without that energy,  some of the energy brought in during the season of light will radiate into the atmosphere and eventually into space and at some point reach a point where the energy levels have dropped enough to freeze water and form ice that seals any remaining heat energy in the waters below it. Once the waters are sealed off by the ice, energy in the air continues to loose heat energy into space and becomes ever colder. So as long as the period of dark is exporting/exchanging more heat than it imports during the season of light we will have a functioning Arctic Freezer.

When the Arctic experiences two things: 1) Importing more heat during the season of light than it had before, and 2) opening the Arctic Freezer door more often during the season of dark, the Arctic Freezer will become more and more strained until it is no longer capable of acting as a freezer.

Why I watch this forum is to try and understand the heat gain and heat loose in the Arctic.

31
Arctic sea ice / Re: The 2019 melting season
« on: August 12, 2019, 05:42:17 PM »
There is another separate thread to compare this year to 2012.  There is too much noise in this thread already when comparing 2019 to other years.  People come to this thread to discuss this year and the dynamics that are causing it to melt not analoging it to other years.

Probably you're right for many users while I honestly come to this and any other thread to learn new stuff, read interesting ideas, facts and opinions and care very little whether they're exactly ON topic or a diversion born from content that is cross-topic.

Further i'm not sure whether a short exchange would be very fruitful it it were traveling form thread to thread, each time a new viewing angle with new input touching other topics would made that appropriate.

Whoever is REALLY interested to get the most out of an exchange of information should perhaps allow for a slightly wider horizon, this would make it much easier to produce real solutions instead of only lamenting the obvious but in fact reaching no escape routes.

In short, too much on topic is killing useful discussions and separates further instead of uniting reasoning as well as people.

If someone is a weatherman reading the melting thread he will provide his input based on his special knowledge and who is too lazy to read a few pages of OT is not really dedicated IMO.

ALL knowledge is useful and there is a level of OT that is very healthy.

I love this thread most of the time and i know that this very post as well as yours are OT and hundreds of complaints about OT, other minor stuff and the often following back and forth bickering are clogging threads far more than the (useful) OT itself.

This is just my opinion which belongs to me and i wrote this because the complaints bother me more than the interesting bywork called OT.

32
For now I'm sticking with last month's estimate: "Between 3.25 and 3.75 million km^2".

I'll keep watching and may exercise my discretion to change it before the poll closes.


July has been at least average and arguably a bit worse than that for the ice. No major storms or events but usually some wind and sometimes a fair bit of sun.

The reference area I always use to compare to is the 80N circle, which encloses an area of about 3.9 million km^2. So I'm guessing the ice extent will end up a little lower than that.


If 'no surprises' then it would probably end up at around 3.8 million but any surprises are likely to push it lower.


Considering the areas where there is currently ice south of 80N:

->  the Pacific side has already almost melted out - more so for this date than happened in any other year besides 2007;

-> The usual 'Beaufort tail' in front of the west CAA will presumably melt away to a large degree as the ice there is already broken up and there appears to be plenty of heat in the water in that region;

-> Yes, the CAA will retain some ice, but it will only be a couple of hundred thousand km^2. To balance that, the Greenland Sea is looking to end barer than in some years, including the record year 2012.


As for the ice detachment from the CAA, the degree to which that has happened is unprecedented in the years of the satellite record. I still expect the pack to drift back to the land before the extent minimum, but it might not. Also, that ice sanctuary has probably seen more heat than any previous year in the record, so some extent will be nibbled away there.


In addition to the possibility of a strong storm anywhere over the ice pack, I look to the Atlantic side for potential 'surprises' even if there is no such storm. The ice there has held on so far, but what about the claimed 'Atlantification' of the water there within the past couple of years? (More salinity and heat.) The Navy thickness map estimate shown below (for 2019-08-09) has relatively thin ice north of Svalbard and the Fram Strait. As we have seen on the Atlantic ice front in some previous years, some of that ice above the shelf of shallower water might disappear fast due to any heat in the water.

The Laptev sector may also get eaten away to well inside 80N.


So here is my guessed boundary, to be compared by eye with the 3.9 million km^2 enclosed by the 80N line. Again, it looks like "Between 3.25 and 3.75 million km^2".


So guessing a second place finish for low extent, behind only 2012. Guessing a record low volume, beating even 2012.

33
Arctic sea ice / Re: Arctic Image of the Day
« on: July 30, 2019, 03:13:52 PM »
Oh, I was just being a little too strong in my sarcasm.  I was positive it was a glacial terminus, having boated around a few in Alaska.  It did get me to register after lurking for several years!

34
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 11, 2019, 07:51:36 PM »
I know it is OT (sry) but I attach this chart for gerontocrat regarding drowning in the Mediterranean and the number of migrants.

Truth is migrants arrive mostly (exception: Syrian war refugees) looking for a job and once they are not welcome anymore, they get the message and don't come anymore
The OT continues.

So we create Fortress Europe - just like Trump in the USA.
How civilised.

Does this stop climate / political / economic refugees increasing?
No. They get trapped in appalling conditions in Libya etc etc.
Out of sight, out of mind.
How civilised.

35
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: July 11, 2019, 06:40:21 PM »
Yes, you and magnamentis may be right but I think that it is just wishful thinking on your part. What happened to the hippie generation? The same thing will happen to these young green voters...unfortunately for all of us. But we will most likely see which of us is right soon enough

The hippies didn't have the scientific community and UN behind them.

36
Arctic sea ice / Re: The 2019 melting season
« on: July 10, 2019, 03:16:41 PM »
One question about this graph on Karsten Haustein's website.
Does this mean the GFS model is underestimating temperatures, or is it the other way around?
See chart at https://forum.arctic-sea-ice.net/index.php/topic,2591.msg212351.html#msg212351

    Non-expert talking, but I've been tracking GFS prediction vs. GISTEMP finalized values for several years.  Looking at the chart and my monthly comparisons indicates that the chart is saying that for Jan, Feb, Mar and Apr the GFS forecast turned out to be lower than the subsequent GISTEMP observations (by 0.06 C averaged across those 4 months).  For May, the GFS forecast turned out to be slightly (0.01 C) above the reported GISTEMP observation. 
   
    June forecasts were running above verification until mid-June.  On June 12 NOAA switched to new FV3-GFS model that so far has been underestimating global surface temperature when compared to verification.

      As of July 10, based on observed GISTEMP for Jan-May, and GFS forecasts for June and July 1-17, the estimate for end of year 2019 average is ca. 1.17 C above 1850-1900.  2019 will be first or second place (85% chance) relative to all other years in 1880-2019 GISTEMP record.  2019 is near record warm with only moderate El Nino effect, and on downward side of solar cycle which has a real but smaller influence.

    Bottom line: The planet continues to warm.  IPCC projections are based on straight line 30-year average projection of  0.2 (+/- 0.1) C per decade.  But a closer look shows that the rate of increase is increasing, e.g. 2009-2019 (11 years to includes a full solar cycle) change in GISTEMP is 0.36 C per decade.  We will be lucky not to pass 1.5C by 2032.  God bless the folks who AFAIK mostly donate their time to create IPCC reports.  But any report that requires consensus of 1500 scientists and 200 governments is bound to be conservative.  If you think IPCC is alarmist, read https://www.researchgate.net/publication/324528571_What_Lies_Beneath_The_scientific_understatement_of_climate_risks
     

     OK, done preaching to the choir.  Not completely on topic for 2019 melting thread, but obviously related.  The energy that is melting the ASI is relentlessly increasing because of our choices.  Being aware means being alarmed, and better yet activated in pursuing solutions that are already available. 

37
Arctic sea ice / Re: 2019 vs 2012
« on: July 09, 2019, 09:55:06 PM »

From NSIDC archive of daily Arctic sea ice concentration images

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/images/2012/07_Jul/N_20120708_conc_v3.0.png
vs.
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/images/2019/07_Jul/N_20190708_conc_v3.0.png

FWIW - Some amateur opinions for consideration and feedback:
1) to my eye July 8 2019 ASI concentration looks more vulnerable than same date 2012.  The few areas where 2019 has more ice are doomed by Sept. anyway.

2) I don't think the extent and area metrics we use to compare between years fully reflect the degraded ice condition in 2019.  Volume has a better chance of reflecting actual situation, but of course it has its own issues.

3) There is still a lot of melt season weather left to go, and as reported in the forum, late July-August 2012 weather was conducive to melt.  While June 2019 was blistering, it remains to be seen what remainder of 2019 melt weather will be like, but it will be hard for 2019 to match late-season 2012.  So that's gives an edge to 2012 in terms of the Sept. minimum extent/area/volume.

4)  And 2012 had the Great Arctic Cyclone. I have to assume that an event of that impact is unlikely in 2019.  But 2019 may bring its own events -- perhaps a couple of less intense events will have cumulatively equal impact as the 2012 GAC.  A return of an Arctic dipole hinted at in the 10-12 day forecast yesterday is an example of hits 2019 could yet deliver to the weakened ice fortress.
   
 5) Of greatest importance -- 2019 includes 7 additional years of a) continued decline of anchoring multi-year sea ice, b) what appears to be qualitative functional changes in ocean heat incursion, c) increased ice pack mobility, d) polar vortex weakening, e) higher atmospheric CO2e, and f) higher global SAT -- by about 0.3C increase between 2012 to 2019.  That's a huge amount of extra energy in the surface layer of the climate system (not even counting the energy buried in the ocean, some of which could affect Arctic sea ice melting this year).  There is a lot of additional heat embedded in the Arctic and surrounding system in 2019 vs. 2012.
   
   6)  Because of #5, I think we really can't know how close to the cliff we are.  But we can be sure that we are getting closer to that cliff every subsequent year of not only persistent elevated GHG level, and not just year-on-year additions, but increases in the rate of increase of GHG loading. 
 
   7) So... 2019 vs. 2012?  A toss up for Sept minimum only because 2012 was such a blow out.  But on the current trajectory it's just a question of when, not if, cumulative progression will push the system below 2012 and make every year below 2012. 

  8) It's natural to focus on  landmarks like Sept. minimum extent/area/volume, but in case you missed it, see the 365-day running average extent the industrious and appreciated gerontocrat posted at https://forum.arctic-sea-ice.net/index.php/topic,2533.msg211770.html#msg211770.  And the even more dramatic 365-day running average volume posted at https://forum.arctic-sea-ice.net/index.php/topic,119.msg211798.html#msg211798.
     More than the ASI status on a single September day, those trends show the larger story of what we are doing to a critical part of our climate system. 

     The world needs the people informed by this forum to spread the news of this existential threat to family, friends, neighbors, colleagues, and politicians.  Please talk about it, that is the essential first step.       


38
Arctic sea ice / Re: The 2019 melting season
« on: June 30, 2019, 01:41:40 PM »
Surge of water into the Chukchi?
The classic geographical features required for a large surge of ocean water (as opposed to a storm surge) is a wide channel, gradually narrowing and gradually shallowing. The Bristol channel / Severn Estuary in England is a classic example. There the surge is associated with Spring (US = King ?) tides.

The bathymetry of the Bering Sea is not a good shape for such a surge.

A long period of a good consistent wind over a long uninterrupted fetch will produce a big swell, hence the tens of metres swells in the Southern Ocean. In the North Pacific the steady wind is there, the long fetch is there. But it is interrupted by the archipelago of the Aleutian Islands. (And a swell does not increase sea level - a 6 foot swell is +/- 3 feet from mean sea level ). So all I can see is some warm surface water being persistently pushed through the Strait to some effect.

The only way I can see a really large influx of water through the Bering Strait into the Chukchi is very low pressure in the Bering Sea lifting sea level, plus very high pressure in the Chukchi depressing sea level. Water flows downhill. That does not exist nor does it look like doing so.

But a wall of water? I don't think so. The physical geography defeats it.

39
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 21, 2019, 08:59:47 AM »
lol .. I wrote a post on posts per day last night and binned it .. although it was to lnvite folks to remove their posts unless they were adding something of value . But then I too realized that all the noise correlates with what's happening ... Thanks Aluminium for the graphic representation . b.c.

  .. ps .. looks like yesterday was an El Nino day ..

40
The rest / Re: Arctic Café
« on: June 17, 2019, 01:30:08 AM »
We need Proccess oriented culture, not Goal oriented culture.

i know what you mean but there is no process without a goal, there will always be a goal that triggers action/activities/processes and once a creature has a goal it will try to reach it either way.

so do animals as well as plants and so does anything in the universe.

also many effects of processes are not know at the start and to kill processes based on suspicion
is only possible in "autocratic" systems.

again, i know what you mean and the thought sounds good but to reach a point where we can reach our goels (ideas, plans etc.) knowing all effects before hand and control them to prevent damage is a bit uthopic.

further who will decide how much damage (effect, cost, exploitation, changes etc.) is acceptable and how much is not ? the people ? they will alway opt for their own interest until the negative effects start to hurt them.

so do the deers who eat up all food within their reach and procreate until the self inflicted food shortage stops the process and their numbers shrink.

so does ever sun that burns it's own matter/energy until it collapses and exploded in a super nova.

it's a law that all things behave like that because equilibrium/symetrie/equality are synonyms for

DEATH

nothing  that is in a perfect level state is alive and nothing really is in that state.

1 week after every german citizen has been give 40.- DM after the war (marshall plan) there were rich and poor. there are better examples but no examples are really needed because it's systemic and i mean laws of physics, laws of nature, universal laws, systemic on the largest scale we can think of and this is why we shall always be correcting and optimizing and open new abysses in the process etc. etc. and so on and so on.

everything else is an illusion, a dream.

the real solutions will come with decimation of population and other heavy tobacco. as cruel as it sounds and is, that's how things work and the survivors will be those who know, accept it and are prepared and a few lucky guys and pals (lottery winners so to say)

those who are not able to evade/escape call those who can cowards while in all history those who
escaped were those who survived in high percentages while surviving heroes are sparse.

if i would have a say, the first thing to do is to prohibit living in areas where survival without heating is not possible and now we can wait for the reactions of all those who live far north and don't want or cannot live more south for whatever, mostly economical as well as emotional reasons.

most humans are trapped, living in a prison and everyone is trying to blame the othes and at the same time refuse facts and telling the truth.

everyone who lives in the cold, has a much larger energy footprint that i would have with a huge fleet of ICE vehicles etc. LOL

could continue endlessly and not one single fact will be welcome to a huge number of human beings defending their own playgrounds.

Conclusion, disaster is inevitable to heal the wounds a species provided to it's environment.
this fact applies to anything in existence down to quarks and quantum physics, nothing is stable
and if it were it were dead.

41
Arctic sea ice / Re: 2019 sea ice area and extent data
« on: June 04, 2019, 12:28:47 AM »
At this date in 2012 there was strong evidence of warmth and early melt ponds but the sea ice extent was close to the average for the previous decade. No one could have foreseen the June cliff and GAC that led to the record minimum in September. It was shocking to witness.

We have no reason to predict a June cliff like 2012, or a GAC this year, but extent loss is way ahead of 2012 at this date. Perils of projections, indeed. We have no good basis at this time for saying that this year is likely headed for second place. No weather model is good enough to predict a GAC or lack of one in August of 2019.

If we look at Nico Sun's albedo warming potential this year is way ahead of 2012 for this date. What happened in mid June through August 2012 was completely unprecedented and we cannot anticipate its recurrence. However, this year could see a record minimum if the present sea ice transport and high pressure patterns persist.

42
Arctic sea ice / Re: The 2019 melting season
« on: June 04, 2019, 12:13:11 AM »
Pearscot, the heat content of the north Atlantic has built up slowly over the decades. It was quite low in the mid 1970s after the effects of "the Great Salinity Anomaly". In the late 1960s the Beaufort gyre dumped a load of fresh water on the Labrador sea and deep water formation slowed down. That likely led to a slow down of the Gulf Stream. Heat built up in the main development region for hurricanes and Camille reached cat 5 while New England had a cold and very snowy winters in the late 60s.

Anyway, the heat content of the north Atlantic has been increasing since the late 1970s and has slowly worked its way north into the subarctic seas. Heat has gradually moved from the subarctic seas to the Atlantic water layer at 300 to 600 or so meters in the Arctic ocean. That water has slowly upwelled along the continental shelves of the Arctic ocean adding to sea ice mass loss over the past few decades.

The fast way for ocean heat to have an impact on sea ice is by storms that track from both the Pacific and Atlantic into the Arctic.  Advection of heat and water vapor on the Pacific side of the Arctic has been very impressive the past few years and has led to the record low sea ice extents in the Bering sea region.

The SST anomaly animation has a lot of information relevant to atmospheric heat advection, but it's on a shorter time scale than the processes that have caused Atlantification of the European side of the Arctic ocean.

43
Arctic sea ice / Re: The 2019 melting season
« on: June 02, 2019, 09:45:54 PM »

i could have used the term "volume" instead of "mass" but i started to dislike the "volume" term because it's mostly associated with "piomas" numbers that are obviously and outright wrong because their algorithm can't manage the new conditions of dispersed and fragmented ice for some reason.


I agree with you, but I am only saying that on a gut level. I stare at, and process, physical data every day and you develop a feel for these things. Sometimes things just don't look right.

That is about as unscientific as one could be, but I chalk it up to our subconscious working in the background. That's my excuse :-)

I have seem PIOMAS values viewed with skepticism before, but does anyone have a handle on exactly where the deficiencies lie and how one might adjust for them?

This is frustrating for me and it ties into a common theme being expressed on the forum right now; Many of our metrics are only telling a small part of the story, and to me, it seems much of it comes down to ice dynamics.

For example, changes in extent are of limited use unless compaction or dispersion are both known and understood. Similarly, the Atlantic side could be seen as not melting when in reality, the ice movement is steadily and rapidly replenishing any ice loss in that area. There are at least half a dozen other examples of this problem but I'm sure you know what I mean. In a nutshell, has the ice melted, refrozen or moved?

I check the graphs and satellite shots regularly, but I realize that I am mostly just trying to read tea leaves, or the entrails of goats. I eagerly await the monthly(?) PIOMAS values as I hope/expect them to tell me the "real" story, yet I am trusting that data less and less.

I recall Prof. David Barber talking about his 2009 trip to the arctic, expecting a large area in the central arctic to consist of solid ice, only to find it to be rotten and virtually no obstacle to the ice breaker. So what is it that we really know for sure? Have we improved much, in ten years?

It may just come down to sitting and waiting, because the weather variability overwhelms the trend signal. That is not easy for analytical types that want to know about something that is both historical as an event, and critical to our future.

44
Developers Corner / Re: Test space
« on: June 02, 2019, 08:24:27 PM »
Here I am testing a throwaway method that enable me to quickly see if the current day continues the incredible sequence of over 180 days of consecutive anti-cyclonic ice rotation. The example simply jiggles back and forth between May 31 and June 01. Indeed this is effective for this purpose. (We have tried other options over the years such as 'color interferometry' of three consecutive days which works but is harder for non-specialists to understand.

The second animation tests an algo for making a quick daily "executive summary" of the most recent developments. It uses AMSR2uhh for land and open water masks, osisaf for quantitative gridded vectors of ice motion, Ascat, ImageJ enhancements of that Ascat, and composition to final image within Gimp. The only technical part is floating arrows off the osisaf in a non-obtrusive but still visible overlay.

The third mp4 tests whether very fast (80ms) back and forth looped display over the 15 Mar -01 Jun 2019 early melt season is visually effective in understanding cumulative sea ice motion which has been truly extraordinary the last 6-7 months.

Towards the end, it shows (rainy?) weather coming in from Alaska over the Beaufort. The file size is so small at this speed at 1.2 MB that a whole year could be shown under forum size limits, possibly even two if water and land masking had been applied.

45
Arctic sea ice / Re: The 2019 melting season
« on: May 31, 2019, 02:07:37 AM »
2019 vs. 2012 on this date, using SMOS microwave data

Probing with microwaves can help to compare current sea ice state with how it was at the same date but 7 years ago, in 2012 - which ended the melt season with the record low extent to date.

Caveat:
IGNORE THE COLOR LEGEND'S NUMERICAL SCALE & LABEL (the color order progression should be valid though) - DURING THE MELT SEASON THESE ARE NOT LEGITIMATE THICKNESS MEASUREMENTS.

Instead, my understanding is that any color other than beige indicates ice that is:
a) thin, ~<50 cm; &/or
b) has concentration well below 100%; &/or
c) has surface liquid water.

The comparison for 29 May:

1) on the Atlantic side, 2012 looks much worse than 2019. The ice edge in 2012 has a much larger fringe inside that is wet &/or thin;

2) extending around to the Laptev Sea, 2012 is also worse;

3) In the Beaufort, both years are bad for the date but 2019 is worse;

4) At the Bering Sea and southwards (Chukchi Sea) 2019 is much worse than 2012, with the ice edge much further in.


In summary, 2012 is worse over the Atlantic half (perhaps the main takeaway here from looking at the SMOS data), but 2019 is worse over the Pacific half.


Also, neither 2012 nor 2019 has significant surface water in the ice interior. In 2012, this arrived and progressed within the next few days and weeks. Given the continuing dominance of high air pressure over the CAB -- which brings clear skies and exposes the ice to direct sun -- I expect that to also happen this year.



Click to view the comparison:

46
Consequences / Blue Ocean Event by Dave Borlace
« on: April 10, 2019, 02:14:21 AM »
Is this video a reasonable depiction of what a BOE would mean?

47
Policy and solutions / Re: UN Climate Agreement - Paris 2015 and beyond
« on: November 21, 2018, 05:28:36 AM »
Re: " If the earth warms how does the radiative balance decrease?"

Let heat coming in from shortwave = Qdot_in, heat going out Qdot_out

right now Qdot_out is less than Qdot_in, 

deltaQdot=Qdot_in - Qdot_out

is greater than zero

a) Qdot_out goes up at T^4

so as earth (actually, top of atmosphere) warms, Qdot_out goes up very quickly and deltaQdot decreases

b)Qdot_out increases as atmospheric CO2 decreases (keeping a bunch of other things the same ...) so again deltaQdot decreases

Re: "Decreasing carbon sinks?"

not considered important over decadal scale

Re: "10 to 20 years to reduce CO2 from 410 ppm to the radiative balance point of 280 ppm? "

No. decadal scale is for peak temperature after emission cease. And then the earth keeps warming for a decade or two, but because of the T^4 factor and CO2 drawdown earth will achieve radiative balance and a peak temperature.. The peak temperature is dictated by cumulative emission. Then temperature will decrease as CO2 leaves the atmosphere.

Earth will remain warmer forawhile until oceanic turnover timescale(1kyr) and continental weathering timescale (10-100Kyr)

I should mention radiative imbalance above preindustrial is about 2.3W/m^2 and because we have already warmed, current imbalance is around 1W/m^2

My guess is that with RCP2.6 we will remain in Eemian for 40Kyr or so ...

sidd

48
Policy and solutions / Re: UN Climate Agreement - Paris 2015 and beyond
« on: November 20, 2018, 01:49:54 AM »
The sun continues to shine adding to the net global heat energy balance every day. So, how does the warming become equalized?

As a body heats up it emits more infrared radiation, so as the Earth heats up it emits more infrared radiation (energy) - some of that increase escapes to space, offsetting the greater amount of heat (energy) trapped by the increased levels of greenhouse gases. At each level of greenhouse gases (and albedo) there is a temperature level that balances energy in / energy out.

This explains it quite well:
https://www.acs.org/content/acs/en/climatescience/climatesciencenarratives/what-is-the-greenhouse-effect.html

"The increased amounts of greenhouse gases human activities are adding to the atmosphere have upset the balance that has been in place since the end of the last ice age. Adding more greenhouse gases decreases the amount of infrared radiation energy leaving the atmosphere. To get the energy back in balance, the surface of the Earth has to warm up, so that it will emit more infrared energy, some of which will leave the atmosphere and compensate for the effect of the added greenhouse gases. Thus, the greenhouse effect, which is essential for creating the climate for life on Earth, is also responsible for the Earth getting warmer than it was before we started burning large amounts of fossil fuels."

49
Policy and solutions / Re: UN Climate Agreement - Paris 2015 and beyond
« on: November 19, 2018, 04:11:34 PM »
Quote
The point that I made in following postings was that if tomorrow CO2 emissions were reduced to zero, this would not prevent the continuing rise in global temperatures. When invited to substantiate this statement, I replied that the application of logic and commonsense was sufficient.
viz
AGW began with CO2 at 280 ppm. What is your reasoning that AGW will stop if tomorrow CO2 emissions cease at 410 ppm?
D-Penguin, your common sense approach makes sense, but two counter-effects undermine it:
* The Earth is much warmer than it was at 280 ppm, so part of the warming effect has already been "equalized". 410 ppm does not necessarily mean more warming - it depends whether we have reached a new equilibrium already. (We haven't though).
* Natural sinks will draw down some of the CO2 in the atmosphere each year, so actual zero emissions will result in a slow downtrend of CO2 concentration. (But these sinks are shrinking and natural emissions are rising,, so we should hurry up).

So warming will continue only for a relatively short time. How long? That's beyond my pay grade.
OTOH, actual zero emissions is something that is very hard to achieve, so don't hold your breath.

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