What is happening to Antarctica?

Answer 1

There are areas of cooling and areas of warming occurring simultaneously in Antarctica, according to recently recorded temperature data. Cooling has been observed in virtually all of the interior. Sea ice around the continent has been growing. However, warming has been observed in much of the water surrounding the peninsula, and parts of the coast, especially those further from the pole. The reason for these changes is believed to be multifactoral.

The cooling of the interior has been attributed to a positive trend in the Southern Annular Mode. This cooling strengthens the polar vortex, inhibiting air from moving across latitudes as much, and enhancing the prevailing winds. This has a profound effect on both temperature and precipitation (and subsequently both sea ice and the ice sheet). See the related question section below for more information about the Southern Annular Mode (SAM).

Loss of ice on the continent has occurred throughout the peninsula and West Antarctica, with smaller increases in East Antarctica. The most recent estimates of ice mass balance were reviewed in Shepherd and Wingham (2007). All studies use different time ranges, methodologies, and often areas. Ice loss in West Antarctica is generally estimated to be around 50Gt/year during the 1990's, accelerating to more than double that the following decade. This has been partially offset by gains in East Antarctica, ranging from about 0 - 60 Gt/year. See the related link to this article. Currently, it is believed that much of the melt in these areas is due to dynamic losses, especially from warmer ocean waters, rather than a warming atmosphere.

Although there are areas of warming in Antarctica, it is not as strongly influenced by global climate change as is the Arctic area, because of the mitigating factor of the Southern Ocean surrounding Antarctica. Additionally, much of its intraseasonal and interseasonal weather variability is governed by the SAM. This is a similar phenomenon to El Nino, in that it extends over a very large region at a low frequency. It is agreed that some of Antarctica's temperature trends are a result of the SAM, particularly since it has been trending toward its positive mode recently. There is also evidence that the SAM is at least partially driven by ozone depletion over Antarctica.

If you view the 2006 NASA temperature map via the related link below, which gives temperature trends in Antarctica during the period of 1982 - 2004, you can see the areas of cooling in blue (you'll see this in the interior and sea ice as explained above), with some places having cooler weather by as much as 0.2 degrees Celsius per year (0.36 degrees Fahrenheit); and the areas of warming in red, with some places (including the areas mentioned above, in much of the water surrounding the peninsula, and parts of the coast, especially those further from the pole), having warmer weather by as much as 0.2 degrees Celsius as well. See the related question section below for information about the difference between weather changes and climate changes.

Over a longer time scale, a 50-year reconstruction of temperature in Antarctica found that the surface temperature has been warming at a rate of 0.12 degrees Celsius. When broken down regionally, it was found that West Antarctica has warmed at a rate of 0.17 degrees Celsius, while East Antarctica has warmed by 0.10 degrees Celsius per decade. This was reported in Steig et al. 2009 (see related link) and is in agreement with previous studies.

Answer 2

Antarctica is getting warmer, though not by quite as much as the rest of the world due to the way the atmosphere behaves in that region. The ice is melting in almost of Antarctica, especially on the peninsula where it is rapidly warming. East Antarctica is in mass balance or may be slightly increasing in mass, though this would be expected in a warming climate with increased transport of moisture from lower latitudes. Overall, Antarctica is in net mass loss.

Answer 3

Ice is the only element that can melt in Antarctica.

Answer 4

Ice shelves round the edges, especially in the Western Peninsula.