## Wednesday, September 12, 2007 ... /////

### Antarctic sea ice at record high

Urbana-Champaign, Illinois - Satellites began to measure the Earth's cryosphere in 1979. Because of a warm summer, the Northern Hemisphere sea ice area has reached new historic lows in 2007. Around August 28th, the new minimum of 2.99 million squared kilometers of sea ice easily surpassed the previous record of 4.01 million squared kilometers set in 2005. These numbers available at the web page of Dr William Chapman and his team at University of Illinois at Urbana-Champaign were widely publicized.

Some analysts have speculated that the new record could be evidence of global warming. But is it? Even though it may sound very complicated, it turns out that the Earth is round. At the global scale, there is not one polar region but, in fact, two. There is also sea ice on the Southern Hemisphere. It turns out that the Antarctic sea ice area reached 16.2 million squared kilometers in 2007 - a new absolute record high since the measurements started in 1979: see this graph.

During the year, the Southern Hemisphere sea ice area fluctuates between 2 and 16 million squared kilometers or so while the Northern Hemisphere sea ice area fluctuates approximately between 3 and 14 million squared kilometers. The climate models predict warming in Antarctica and they are increasingly inconsistent with the observations.

The South pole winter is now about 0.6 Celsius cooler than in 1957.

Via Marc Morano.

#### snail feedback (10) :

See BOTH graphs. THey are in the same directory, one next another.

South
North

Dear Arivero, I've surely seen both, and in fact, dedicated 1/2 of this article to the North even though there has been another article dedicated purely to the North in the summer. Surely you don't want to say that the North is discriminated against, do you?

Actually the ice data and some other warming data seem to indicate a discrimination N/S, do you think? But if we are speaking global, it seems we need to add both. After all, you do not get the euler characteristic by integrating the local properties of only a part of a manifold, but the whole.

Dear Alejandro, I find it completely obvious that the Arctic climate is given much more room in all media because a certain class of people finds such an arrangement much more convenient because it fills their pockets by dirty money.

Ad hoc integrals over the Earth are just ad hoc integrals over the Earth and they surely don't have any importance that would be even remotely comparable to the Euler character of a manifold.

My point here is that even the question about the sea ice that is often presented as evidence for "climate change" is not global in character. By "global", I suppose that people mean something that influences pretty much all regions of the world. That's obviously not the case with the sea ice because as much as 1/2 of the planet disagrees with the assertions of the ideology.

If one has a theory (here: "global warming") and it only qualitatively agrees with one-half of the observations, as far as I can say, it is a falsified theory.

The recent (30 years) warming is largely confined to the Northern Hemisphere and theories that fail to explain this rather basic observation are in bad shape - do you agree at least with this trivial statement?

Indeed I agree. The theory, at least in its more divulgated form, is still in poor shape, but at least the experimentalist keep recording data.

Besides, a decent theory should explain why the ozone hole opened first in the south, where oceanic data seems to be more stable than in north.

Why would global warming models, which deal with greenhouse gases in the troposphere, be expected to predict the ozone hole, which results from chemical reactions in the mid and upper stratosphere?

For what it is worth, just a little research around the 'net reveals that the annual onset of the ozone hole requires formation of specifics kinds of ice crystals that requires temperatures of -78 Celsius.

While that temperature occurs with regularity for long periods of time in the stratosphere above the Antarctic, it occurs less frequently, and for shorter periods elsewhere in the world. Thus, the initial appearance of the ozone hole above Antarctica is not mysterious, nor is the fact that it is larger and lasts longer than other ozone holes that have at times appeared in other places, primarily the Arctic.

All of this discussion is with reference to Antarctic sea ice area.
Are there any data about Antarctic ice (land and sea) volume?
Surely, in the long run, that is far more significant.
By the way, I hold no brief for either side of this debate -- I merely seek the truth.
Having said that however, I have recently returned from a climbing trip to Mt. Kenya which I used to climb regularly 20 years ago. The famous Diamond Glacier is now a small patch of snow, and the Lewis Glacier is dramatically smaller. Flying over Kilimanjaro shows a similar decline.

Dear Scotjack, I surely think that you are not right.

The sea ice area is more important than sea ice volume because it has at least some impact on the world: it co-determines the average albedo of the Earth and it influences navigation on the oceans.

Neither volume nor area of sea ice determine the sea levels because of Archimedes' law.

The volume is more difficult to measure for the same reason - it has a smaller impact on the things that matter.

The volume of ice sheets on the land are a different topic and they are also measured because the volume is dominated by the upper boundary, nor lower boundary, whose shape can be measured from space.

The average thickness - the volume/area ratio - is determined primarily by the frequency of temperature fluctuations. If you assume them to be constant, there is no reason that in the long run, the area and the volume would have different trends.

The glaciers have been retreating since 1850 or so as the Earth was leaving the Little Ice Age.

Best
Lubos

The climate models predict warming in Antarctica and they are increasingly inconsistent with the observations.

Climate models of temperature and sea ice trends in Antarctica are varied and none purport any certainty in the short term - the period of interest for the post above. Recent trends can say little about the efficacy of models when the modelers themselves say that their models have little efficacy in the short term.

TAR (IPCC 2001) made no temperature or sea ice projections for the short term because data was too sparse, certain processes little understood, and therefore projection models were given very little confidence - not enough to render conclusions on the Antarctic in TAR, at least. The TAR confined its projections to precipitation, for which there was more confidence, stating that it should increase.

AR4 (IPCC 2007) projected sea ice decrease in the long-term, but gave no indication of short-term projections.

The surface mass balance (ice sheets) for Antarctica are projected to increase slightly in the short-term due to the increased precipitation. Even with the melt offset of due to soot, ice sheet trends are expected to increase.

"General Circulation Models indicate that the Antarctic Ice Sheet will receive increased snowfall without experiencing substantial surface melting, thus gaining mass and contributing negatively to sea level."
AR4 Ch. 10, Regional Projections, p. 751 (PDF)

Because there is much more ocean in the Southern hemisphere, tropospheric heat is more readily absorbed. It is generally considered that the Southern polar region will lag the rest of the globe in warming. There is a general consensus amongst models that Antarctica will warm significantly, but these trends are not expected in Antarctica until about 2040 (barring some coastal regions).

The Antarctic is vast and data is not well gridded. There are processes at play in the Southern Polar region that are not matched, or not matched in degree with the Arctic. Antarctic ice mainly rests on land where there is no land under the Northern pole. Ozone depletion is severest over the Antarctic due to colder air and stratospheric cloudiness accelerating the phenomenon. From the article you linked on temperatures;

Bromwich said that the increase in the ozone hole above the central Antarctic continent may also be affecting temperatures on the mainland. "If you have less ozone, there's less absorption of the ultraviolet light and the stratosphere doesn't warm as much."

That would mean that winter-like conditions would remain later in the spring than normal, lowering temperatures.

"In some sense, we might have competing effects going on in Antarctica where there is low-level CO2 warming but that may be swamped by the effects of ozone depletion," he said. "The year 2006 was the all-time maximum for ozone depletion over the Antarctic."

Agenda-driven articles on Antarctic temperature confine their analysis to only areas of the Antarctic that show warming, or, if they do acknowledge gridded variability, do not give a mean figure - because a mean figure would show no significant trend.

While I agree that the media (assisted by climate scientists) has mainly focused on the Arctic, with it's obvious decline in sea ice and rising temperatures, I suggest that the article above does no better - with respect to providing a balanced report on the subject of the Antarctic. Saying "models predict warming" gives no account of the rate, period, or whether interannual or decadal variability (the latter was projected to be largish for Antarctica in the coming decades) is accounted for.

The recent trend in sea-ice does not fall outside model projections and the lack of warming is consistent with observations since 1978 and with the general consensus of studies - for the short-term.

The local variabilities around Antarctica are another matter.

barry

Sydney, Australia