太阳辐射和大气环流在青藏高原气温季节变化中的作用

利用1981~2010年共30a的美国国家环境预报中心(NCEP)再分析格点资料,对青藏高原及其周边温度的季节变化及可能机理进行了研究.发现:地表24℃等温线2~3月和11月的南北跳动可能是太阳辐射和季风环流共同作用的结果;200hPa温度的季节变化早于地面和500hPa,其原因可能与平流层爆发性增温造成的能量下传有关;青藏高原的低温与低的大气逆辐射密切相关.该结果可为进一步研究青藏高原气候变化及其规律提供参考.

The role of solar radiation and atmospheric circulation in the seasonal temperature changes of Qinghai-Tibet plateau

Based on the 30 year data from 1981 to 2010 of the US National Centers for Environmental Prediction (NCEP), the process of seasonal temperature changes in Qinghai-Tibet plateau and its surrounding areas as well as the possible intrinsic mechanism are studied. The results show that the 24℃-isotherm of earth surface exhibits a sudden jump between the north and south about 18 latitudes in February-March and November, which is speculated to be the result of the joint effects of the solar radiation and the monsoon circulation. The seasonal temperature change on 200 hPa is earlier than on surface and 500 hPa, presumably due to the downward energy transfer from the sudden warming stratosphere. The surface temperature in Qinghai-Tibet plateau is closely related to lesser downward longwave radiation flux. The results will provide useful hints for further research on climate change in Qinghai-Tibet Plateau.