Sunday, May 24, 2009

Antarctic Ice Extent

This January, during the southern summer, I went to Antarctica. I wanted to see it. It was wonderful, glorious and we had fantastic weather, but we hit it lucky. The two cruises immediately before us and the one after us had weather so bad that they couldn't land but once each trip.

I will say that it was cold down there, even in January, when it is the warmest. Today the Global warming hysteriacs tell us that Antarctica is de-icing. Everything is slipping into the sea. But of course this seems contradictory with the fact that over the past 30 years the Antarctic sea ice has grown year after year. While the Arctic ice has declined, Antarctica's ice has been getting bigger each and every year for the past 40 years.



the Arctic plot is shown here.



Now, one thing that most people don't understand is that the Arctic and Antarctic are out of phase with each other--something that shouldn't be if CO2 is the cause. CO2 should affect the Arctic and the Antarctic equally because it is affecting the radiative escape of heat. But as we can see they are out of phase.

"The last glacial and deglacial periods were characterized by millennial-scale shifts in global climate. Records from Greenland ice cores! and North Atlantic sediments suggest that high latitudes in the Northern Hemisphere were repeatedly subjected to large and abrupt fluctuations in temperature, commonly referred to as Dansgaard-Oeschger oscillations. In contrast to the abrupt changes observed in the north, temperature fluctuations over Antarctica were more gradual (warming and cooling over hundreds to thousands of years) and approximately out of phase with their northern counterparts'. Recent ice-core evidence from the Atlantic sector of Antarctica reveals a direct relationship between the extent of warming across Antarctica and the duration of cold, stadial conditions over Greenlands. The contrasting behaviour of temperature variations over Greenland and the North Atlantic as compared with Southern Hemisphere records has led to the notion of a bipolar seesaw, whereby changes in the strength of the Atlantic's conveyor circulation or, more precisely, the Atlantic meridional overturning circulation (AMOC) affect the distribution of heat between the South Atlantic and the North Atlantic and more widely'? Modelling results suggest that a reduction in the strength of the AMOC (for example as may be caused by an input of fresh water to the North Atlantic) would give rise to an immediate decrease in northward heat transport. As a result, surface air temperatures over the North Atlantic would cool and those over the South Atlantic would warm. The transmission of these anomalies between the North Atlantic and the South Atlantic may take on the order of a few decades." Stephen Barker, et al, "Interhemispheric Atlantic Seasaw response during the last deglaciation," Nature, 457(2009), p. 1097

Of course, the hysteriacs won't tell you about this. They only want to get funding from you in the form of taxes. They scare you with the Arctic, and tell you bed-time scary stories about Antarctica de-icing, but don't show you the pictures of the Antarctic sea ice I just showed you. In other words, they hide data from you.

2 comments:

  1. Um. You do realize that the author list of the paper you just extensively quoted is full of so-called "hysteriacs"? Eg, on the author list is Wallace Broecker, who was apparently the first person to use "global warming" in a scientific paper, back in the 1970s, and who recently was given an award for which the press release states, “Prof. Broecker has been an eloquent educator and a forceful champion of efforts to address the risks of greenhouse gas emissions from human activities”.

    But us hysteriacs are hiding this information. Oh yes, Hiding it _deep_ inside, well, the frequently asked questions section of the NSIDC Arctic Sea Ice News, and the front page of Cryosphere Today, the two most commonly linked locations for Arctic sea ice news. Maybe not all that deep after all.

    Also, you've totally misread the Barker paper. He is talking about historical events at the glacial/interglacial boundary, not about current conditions, where the Antarctic circumpolar vortex, the ozone hole, and the deep Southern Ocean are all theorized to offset or slow warming. CO2, ceteris paribus, should warm the Arctic and Antarctic about equally, yes. But there are plenty of regional effects superimposed on top of the CO2 warming. The south-eastern U.S. is a good example, which has not evidenced much warming yet.

    Also, I think one of the things that you don't really get is that most of us hysteriacs don't think we've seen large temperature changes yet: it is the future temperature changes that theory tells us are fairly probable that scares the pants off of us. Right now, signals are just barely beginning to emerge from the noise. We could wait until the signals were undeniable... but the problem is that due to the inertia in the system that will be too late. The fuss about the Arctic sea ice was because it looked like it was disappearing _much_ faster than anyone was expecting. If (and it is still an if) the rapid decrease of 2007 was an indication that Arctic sea ice is more sensitive to global temperature change than we expected... well, that undeniable signal may come sooner rather than later. I'm still hoping that 2007 was an outlier, and we'll return to the slower rate of loss that was evident from 1979 to 2006.

    A couple more notes: The Antarctic ice growth is much smaller compared to year-to-year Antarctic ice variability than the Arctic loss is compared to its variability. Also, at least to the best of my knowledge, Antarctica is still losing ice mass according to the GRACE satellite (though I haven't looked into that recently). The IPCC (hysteriac) estimates of sea level rise assume that Antarctica's contribution over the next 100 years will actually be negative (eg, increasing ice mass) because increased precipitation in the interior will outweigh increased melt (Table 10.7, IPCC AR4). So really, reality is actually _worse_ than the hysteriac projections (though again, like the Arctic sea ice, it has yet to be seen if this is a short term hiccup or a longer term problem).


    Also, I might check your definition of "each and every year". I do not think that phrase means what you seem to think it means.

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  2. I know who Broecker is Dave. I have read his stuff for about 30 years as I have worked in the deep water. You clearly misunderstand my use of the term hysteriac. A hysteriac is one who says we had better do something or all of civilization will die, and they are numerous. I personally don't count Broecker among the histeriacs.

    I will acknowledge that the cryo site has the data, you are correct on that, but how many of the regular people go to that site? How often do you see in the newspapers and magazines that Antarctica is enlarging its ice? You only hear horror stories about how it is all about to end, and yes, you hear it even in the scientific literature.

    Dave I love the apology you advance for why CO2 doesn't affect Antarctica. It is amazing how the human mind can ignore any and all data if it wants to. And I love your faith statement that signals are just now emerging from the noise. I have spent my career in signal analysis and the signal is either there or not. When it is, one doesn't have to make statements like you do.

    And I would suggest some better understanding of math when you make the statement, "Antarctic ice growth is much smaller compared to year-to-year Antarctic ice variability than the Arctic loss is compared to its variability."

    Here is the thing Dave, Antarctic Ice extent is about 2x that of the Arctic. If they both varied the same amount, your statement would be true. But, Dave, I just checked up on your statement. If I understand what you are saying correctly, the Arctic average change is about 2% per year while Antarctica changes by 1.6% per year. Not all that much different. Certainly not something to be worried about.

    If you were saying that the DECLINE over the past 30 years is greater in the Arctic, then I would have to agree

    Finally, I would agree that if the world warms, we will see more precipitation in the interior of Antarctica. So far we are not seeing that increase and yet Antarctica is said to be warming by all the hysteriacs. Maybe that is an indication that it really isn't warming, could that be Dave?

    As to GRACE I looked at it this week and just now re-looked. Most of the losses are in West Antarctica, which is being warmed by ocean currents, not CO2.

    The westerlies are the prevailing winds in the middle latitudes of Earth’s atmosphere, blowing from west to east between the highpressure areas of the subtropics and the low-pressure areas over the poles. They have strengthened and shifted poleward over the past 50 years, possibly in response to warming from rising concentrations of atmospheric carbon dioxide (CO2). Something similar appears to have happened 17,000 years ago at the end of the last ice age: Earth warmed, atmospheric CO2 increased, and the Southern Hemisphere westerlies seem to have shifted toward Antarctica (5, 6). Data reported by Anderson et al. on page 1443 of this issue suggest that the shift 17,000 years ago occurred before the warming and that it caused the CO2 increase. The CO2 that appeared in the atmosphere 17,000 years ago came from the oceans rather than from anthropogenic emissions. " J. R. Toggweiler, "Shifting Westerlies," Science, 323(2009, March 13, 2009, p. 1434

    Those winds shifted again 40 years ago, just about the time that the Keeling Curve has a dog-leg


    "The faster the ocean turns over, the more deep water rises to the surface to release CO2," said lead author Robert Anderson, a geochemist at Lamont-Doherty. "It's this rate of overturning that regulates CO2 in the atmosphere." In the last 40 years, the winds have shifted south much as they did 17,000 years ago, said Anderson. If they end up venting more CO2 into the air, manmade warming underway now could be intensified." "Wind Shifts May Stir CO2 from Antarctic Depths" Lamont-Doherty
    http://www.ldeo.columbia.edu/news-events/wind-shifts-may-stir-co2-antarctic-depths

    And thanks for the condescension in your English lesson. Condescension so becomes you.

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