全球变暖背景下的南极地区气候变化

ANTARCTIC CLIMATE CHANGE UNDER THE BACKGROUND OF GLOBAL WARMING

南极地区气温冬季、春季和秋季都有上升趋势，而夏季则有下降趋势，年平均气温也趋上升。气温上升趋势最强烈的是冬季，其次是春季；降水各季和全年都有增加趋势。在年际尺度上，年均气温和降水与南极涛动指数是负相关，南极涛动对不同区域影响的方式和程度也有区别。从长期变化趋势来看，气温、降水和南极涛动指数都有上升趋势。

This paper analyzed the characteristics of surface temperature and precipitation changing over the Antarctic region in the past two decades based on the NCEP-NCAR reanalysis data. Under the background of global warming, the temperature of Antarctic region increases in winter, spring and autumn, but the summer temperature tends to drop. The annual temperature also increases. The strongest warming occurs in winter. Antarctic precipitation of all four seasons in increasing. The variation of temperature and precipitation has different features in different areas. Evidence shows that the atmospheric circulation may play an important role in making the difference between places. Annual average AOI correlated to surface temperature and precipitation of Antarctica is -0.55 and -0.31 respectively, and the temperature to precipitation is 0.57. These facts show that in annual time scale the variation of surface air temperature and precipitation are both affected, or controlled, by the AOI. But, all AOI, temperature and precipitation have the same uprward trend, especially the trend of AOI and precipitation is pronounced. One feasible explanation is that under the background of global warming, Antarctic temperature is also increasing, higher temperature means more moisture in air, then increasing precipitation can be expected. Many general circulation models also suggest that precipitation amounts in polar latitudes will increase under the double CO 2 scenarios, especially in Antarctic region.