Antarctic Ice Grows as Arctic Ice Declines
by Jeremy Elton Jacquot, Los Angeles on 01.10.08
Image courtesy of zutalegh
With stories of melting glaciers and sea ice dominating the headlines, it may come as a surprise to some to hear that Antarctica - defying the unlucky fate of its northern cousin - has actually gained over the last two decades. Indeed, while scientists noted declines in the amount of sea ice between 2000 and 2002, satellite records have pointed to a steady half a percent yearly gain since 1978.
Climate models have consistently shown that Antarctica has responded much more slowly to global warming than has the Arctic. As Stephen Ackley, a scientist at the University of Texas, San Antonio, put it: "Arctic sea ice is well ahead of the models, and Antarctic sea ice is well behind what the models project." More recent studies have also determined that - outside the tropics - Antarctica displays the strongest climate response to the El Niño-La Niña cycles, suggesting the presence of many important feedbacks between sea levels, ice and air in the Southern Ocean that have yet to be elucidated - and serve to cloud the current climate picture.
Despite the gains of Antarctica's sea ice, the larger region - encompassing the Bellingshausen and Amundsen Seas - has suffered as a whole: glaciers in these seas, which flow from the West Antarctic Ice Sheet, are now losing ice to the sea faster than they are being replenished. This "very big threat to glacier ice," as Columbia University's Xiaojun Yuan calls it, could be the result of warm water upwelling near the coast - a consequence of global warming's impact on regional wind patterns.
So what's to account for the differences between Antarctica and the Arctic? Large geographic and oceanographic differences between the poles - an open sea in the south versus an almost landlocked sea in the north - facilitate the buildup of long-lasting, multiyear ice in the Arctic, as opposed to thin, seasonal ice in the Antarctic. As a result, scientists explain that accurately ascribing long-term trends in ice cover to both becomes very difficult. Some recent studies have posited that bacteria and algae living in the ice could trigger the production of large amounts of dimethyl sulfide, thus potentially limiting global warming's effect in the region.
According to the latest models, the Antarctic sea ice will start to gradually decline over the course of the century. Scientists will be keeping a close eye on the mass of Antarctica's sea ice over the coming months; because ice in the Arctic started to melt from underneath before any major changes were noted, scientists want to ensure that they don't miss crucial shifts in the sea ice that a satellite picture might not pick up on.
Via ::Christian Science Monitor: As arctic ice melts, South Pole ice grows (newspaper)
See also: ::Belgium Unveils Solar-Powered Climate Research Station, ::Arctic: Ice-Free by 2013?
According to a study released by NASA in September of 2007 this is not true. There has been recent disturbing melting of Antarctic ice 500 miles inland and at altitudes of up to 1.2 miles. That is scary!
http://www.thedailygreen.com/environmental-news/latest/7016
I blogged this a few weeks ago.
My conclusion from all this data is that we still need to wait and see before sounding the alarm bells. While I still think a green lifestyle is best, we only serve to confuse the public by too quickly jumping on the shrinking northern ice cap as evidence of Global warming without explaining why the Southern Ice caps are growing.
Antarctic ice increases by .5% yearly? How does this compare in Volume to the Arctic ice being lost? We're talking %ages of the whole here, right? Any more info on the stats?
"There's an upside to the extreme cold temperatures northern Canadians have endured in the last few weeks: scientists say it's been helping winter sea ice grow across the Arctic, where the ice shrank to record-low levels last year.
Temperatures have stayed well in the -30s C and -40s C range since late January throughout the North, with the mercury dipping past -50 C in some areas.
Satellite images are showing that the cold spell is helping the sea ice expand in coverage by about 2 million square kilometres, compared to the average winter coverage in the previous three years."
You can all relax now..