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Thursday, September 19, 2013

Wind and ice in Antarctica as seen through the eyes of science deniers at WUWT

Sou | 3:19 PM Go to the first of 2 comments. Add a comment

Anthony Watts and the readers at WUWT are nothing if not inconsistent.

Anthony has put up another of his "Claim:" headlines as he's been doing lately to denote that a new scientific paper has been released for him and his readers to disbelieve.  (Anthony Watts rejects science that he thinks might result in his having to pay more taxation. Yeah, that's what he said.)  The WUWT article is archived here.

Anthony's latest is a new paper by Jinlun Zhang linking the increase in winter sea ice in southern oceans with more intense polar winds.  From ScienceDaily:
"The overwhelming evidence is that the Southern Ocean is warming," said author Jinlun Zhang, an oceanographer at the UW Applied Physics Laboratory. "Why would sea ice be increasing? Although the rate of increase is small, it is a puzzle to scientists."
His new study shows that stronger westerly winds swirling around the South Pole can explain 80 percent of the increase in Antarctic sea ice volume in the past three decades.
The polar vortex that swirls around the South Pole is not just stronger than it was when satellite records began in the 1970s, it has more convergence, meaning it shoves the sea ice together to cause ridging. Stronger winds also drive ice faster, which leads to still more deformation and ridging. This creates thicker, longer-lasting ice, while exposing surrounding water and thin ice to the blistering cold winds that cause more ice growth.
Antarctic sea ice concentration changes from 1981 to 2011.
(Credit: U.S. National Snow and Ice Data Center)
Source: ScienceDaily.com

Windy inconsistency

I call "inconsistent" because Anthony denigrates the study with his "Claim:" headline and many of his readers do the same.  They want to dispute the finding that intensified winds can explain most of the increase in winter sea ice down south, but jump on the idea that wind can cause a decrease in summer ice in the Arctic. For example from a WUWT article on the record sea ice melt of 2007 (archived here):
In simpler terms, polar wind patterns changed and blew sea ice further south to warmer waters than it normally would. Sea ice can easily be wind driven.
I wonder if that’s the same mechanism that caused loss of Arctic sea ice in the 1920-30′s?
Another example from WUWT on the record sea ice melt of 2012 (archived here):
Many climate activists have sought to downplay the significance that the Arctic cyclone played on this year’s summer sea ice in the Arctic. But this new inconvenient video report from NASA now makes the warmists’ attempt to deny the cyclones role in 2012′s Arctic sea ice conditions — impossible.
Of course the above is just another one of Anthony Watts' strawman arguments.  His "many climate activists" most probably wouldn't have denied that a storm played a part in breaking up sea ice in the Arctic last year. As noted by Neven on his sea ice blog last year in relation to that cyclone:
The effects of this storm on the sea ice concentration maps are in plain sight. Slowly sea ice area and extent data are trickling in and for now the changes are quite large. 
What is a fact is that it didn't cause the record low in Arctic sea ice extent.  The record low ice extent wouldn't have been the record it was if not for global warming.


From the WUWT comments

The comments are archived here with the main WUWT article.  Here is a sample:

StuartMcL complains about the colour scheme of the diagram and proposes a (conspiracy) theory:
September 18, 2013 at 6:09 pm
Every other climate related chart that I’ve seen shows reds for warmer and blues for colder. I wonder why this one uses the opposite. It wouldn’t be to make it look more “scary” would it?

Bob Tisdale hasn't read about the study, which uses observations, and doesn't like models (though he uses them when it suits him) and says:
September 18, 2013 at 6:17 pm
Modeling study? Are the current batch of climate scientists incapable of studying data?
Oh, for the good old days before fatally flawed climate models.

James Allison acknowledges the role of wind in both polar regions though he doesn't get it quite right when he says:
September 18, 2013 at 6:20 pm
So there we have it – wind pushes ice away from the Arctic however pushes it toward the Antarctic.

Jeff D is very disturbed that scientists keep on looking for explanations and insist on adding to the world's knowledge.  To scientific illiteratis like JeffD, scientific research is anathema:
September 18, 2013 at 6:29 pm
They cannot let the increase in ice stand. They have to come up with some cock and bull study to make us believe that it is still worse than we thought. Will the insanity ever end..

Mike Jowsey is a plain vanilla science denier and says:
September 18, 2013 at 6:35 pm
I guess he didn’t get the memo – the climate is not warming.

4 eyes is a proudly semi-illiterate member of the illiterati and says:
September 18, 2013 at 6:49 pm
Truly settled science – no doubt. These guys should be de-funded. Immediately. Since the science was settled years ago there is no need for anymore work. Especially if it’s this quality. This must be embarassing for the scientists who follow the scientific method and make models that history match the facts.

Surfer Dave thinks that all models are bad and says:
September 18, 2013 at 5:52 pm
“model experiment” is an oxymoron. Why do they think their model comes anywhere near to reality? How does one calibrate such a model before doing an “experiment” with it. Totally bogus “science”.

Peter Foster theorises from his armchair that he knows more about Antarctic oceans than does Jinlun Zhang, Senior Principal Oceanographer from the Polar Science Center of the University of  Washington and says:
September 18, 2013 at 7:12 pm
I wonder if Zhang has ever been to Antarctica. i wonder if he has ever spent time working on the sea ice or on a ship sailing through it. No matter how strong or cold the wind, if the sea surface water is not cold enough it will not freeze and once it does freeze the wind has no effect on the thickening of the ice. That occurs by radiation of heat through the ice from the water underneath. Sea ice thickens by water freezing from underneath. But then you would think a scientist studying sea ice would know that wouldn’t you. Perhaps that is the difference between the armchair theorists and practical scientists.
By the way, is there any actual data on the circumpolar wind strength from sub Antarctic islands or is this just guess work on Zhang’s part.

Tez doesn't quite understand a letter he got from a "Professor" working on the Ross Ice Shelf and says:
September 18, 2013 at 7:26 pm
They dont know why the sea ice is growing. Wind patterns is just as much a guess as the theory that it is due to the melting ice shelves cooling the adjacent waters.
A Professor currently working on the Ross Ice shelf wrote to me stating that the increased sea ice was due the the ozone hole allowing cold air from high above to descend on the Arctic ocean. (which Tez later corrected to Antarctic)
This increase is difficult to explain away in a warming world and I dont think they have found the answer yet.
(The ozone hole in the south affects the polar winds.  Here is an article at Climate Central that discusses a recent paper by Waugh et al (2013) in Science: The Impact of Stratospheric Ozone Recovery on the Southern Hemisphere Westerly Jet, DOI: 10.1126/science.1155939)

Jim Steele offers his own brand of pseudo-science, talking of katabaitc (sic) winds "blowing equator-ward" and disputing Zhang's findings (excerpt):
September 18, 2013 at 7:33 pm
Besides the false claim that ice is growing where it is warming, the model actually offers a good explanation for the change in Arctic sea ice. Most of the Antarctic sea ice is driven by the katabaitc winds blowing equator-ward from the continental interior. Unconstrained by other continents, most of the Antarctcc sea ice expands unimpeded with much less ridging than witnessed in the Arctic. For that reason most of Antarctic’s sea ice is thin first year ice with very little ridging that is claimed by the model. Each winter the Antarctic sea ice extent is much greater than observed in the Arctic, but Antarctic sea ice also melts more rapidly each summer precisely because there is so little ridging .

From the Australian Antarctic Division (my bold italics):
Radiative cooling over the Antarctic ice sheet produces very cold, dense air that flows away from elevated areas and is replaced by subsiding air from above. The resulting katabatic winds accelerate downhill, enhanced by the confluence of glacial valleys. Katabatic winds blow with great consistency over large areas. At the coast they lose their driving force and soon dissipate offshore.
Low-pressure systems near the Antarctic coast can interact with katabatic winds to increase their strength. Resulting wind speeds can exceed 100 km/h for days at a time. Wind gusts well over 200 km/h have been measured.

And a diagram illustrating the wind flows down from the mountain ranges in Antarctica, from Stephanie in Antarctica:




Bill Illis says "it's not happening" (extract):
September 18, 2013 at 5:37 pm
First, the oceans around Antarctica are not warming. All the datasets show no warming going back more than 100 years and there is clearly recent cooling given the sea ice conditions.

Oakden Wolf responds to Bill Illis's denial, writing (with insight into the collective mind of WUWT) in part (my paras):
September 18, 2013 at 8:26 pm
Wow. History. I read Bob Illis’ comment that the Southern Oceans had not warmed for 100 years, and that seemed wrong. I did a little digging, and discovered a remarkable WUWT thread from about three years ago, “Dr. Curry warms the Southern Ocean”, in which this issue was discussed at length. And I was reminded that I participated in that thread, and offered SEVERAL references indicating the Southern Ocean was warming.
My references were only mildly considered, and they were dismissed with quite inadequate effort, because the principal in that thread was hunting bigger game than I, a small fish to fry.
Nonetheless, the references remain, and they are quite compelling that the Southern Ocean is warming. I note that one key paper, which I provide the citation and link to below, was not addressed at all in that somewhat forgotten thread. So I’ll also provide the abstract for that one.
Gille, Sarah T., 2008: Decadal-Scale Temperature Trends in the Southern Hemisphere Ocean. J. Climate, 21, 4749–4765. doi:http://dx.doi.org/10.1175/2008JCLI2131.1
http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2131.1...
... So I think it’s fairly clear that the Southern Ocean has been and is warming, and efforts to understand the slight increase in Antarctic sea ice extent need to incorporate that.



Zhang, Jinlun. "Modeling the impact of wind intensification on Antarctic sea ice volume." Journal of Climate 2013 (2013). doi: http://dx.doi.org/10.1175/JCLI-D-12-00139.1

2 comments:

  1. And what do we see when we join up the dots?

    We see that the strengthening zonal wind fields are increasing the rate of upwelling of warm, coastal waters around Antarctica, which in turn is increasing the rate of basal melt of ice shelves currently inhibiting glacial outflow from the WAIS/EAIS.

    So - surprise! - the much-touted-by-deniers growth in Antarctic sea ice extent is directly linked to the increasing rate of ice mass loss from the continent, especially the WAIS.

    Here's a useful backgrounder on the evolution of this hypothesis.

    See here for latest observational overview of basal melt rates (be sure to expand the first technical figure) and:

    Pritchard et al. (2012) Antarctic ice-sheet loss driven by basal melting of ice shelves.

    Holland & Kwok (2012) Wind-driven trends in Antarctic sea-ice drift.

    ReplyDelete
  2. An interesting thing the denier blogosphere seem to miss about Antarctic ice is that ice extent really only have a meaning when the sun is shining on the ice as that is when its albedo has a cooling effect. Every warm season in Antarctica virtually all the sea ice disappears, hence it doesn't contribute to cooling at all when the sun is baking the place. What they also miss is the actual decline in mass in Antarctica (and Greenland) that indicates that its melting and not cooling.

    ReplyDelete

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