Global Outlook for Ice & Snow
Antarctic sea ice. Photo: Mlenny/iStockphoto.com
There are far fewer observations of sea-ice thickness for the Antarctic than for the Arctic because of the lack of submarine measurements. It is therefore not possible to detect any trends in Antarctic sea-ice thickness over recent decades. The reasons for the very different trends in Arctic and Antarctic sea-ice extent over recent decades are not known at present and resolving this important ques- tion is a high research priority. Researchers are exam- ining changes in the atmospheric circulation of the two polar regions as well as changes in ocean circulation.
Southern Hemisphere
Whole S Hemisphere Bellingshausen Sea
+1.2
-5.3%
Weddell Sea Indian Ocean
+1.0 +1.1 +1.2
West Pacific Ocean
Ross Sea
+4.8 Change in annual mean sea ice extent (% per decade)
Figure 5.8: Regional changes in Antarctic annual mean sea-ice extent (% per decade) for the period 1979–2004. Source: Data courtesy of NASA 2007a 9
CHAPTER 5
ICE IN THE SEA
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