亚洲冬季大气动能的时空演变特征及其与中国冬季降水和温度的关系

利用1968～2008年NCEP/NCAR再分析资料、中国测站的降水量和温度资料,分析亚洲冬季大气动能的时空演变特征,探讨与其对应的大气环流异常特征以及大气动能的变异与我国降水量和温度异常的联系。结果表明:亚洲冬季大气动能的主要变异中心在东亚西风急流区,该地区的冬季大气动能存在明显的年际和年代际变化。冬季,我国中东部至日本以东到西北太平洋上空大气动能的减弱(增强)与对流层中高层东亚西风急流的减弱(增强)密切相关,并可导致我国东部大部分地区降水量的偏多(偏少)和我国东北地区温度的偏高(偏低)。青藏高原西南侧大气动能的增强(减弱)则与该地区对流层中高层南亚西风急流的增强(减弱)有关联,并导致冬季我国东南地区降水量的偏多(偏少)和我国广西、贵州和四川一带温度的偏低(偏高)。在冬季,亚洲大气动能的变化可能主要通过影响亚洲西风急流的变化来造成我国冬季气候的变异。

Spatial and Temporal Variations of Asian Winter Atmospheric Kinetic Energy and Their Linkage with Winter Precipitation and Temperature in China

The spatial and temporal variations of Asian winter atmospheric kinetic energy, the abnormality of atmospheric circulation caused by these variations, and their linkage with precipitation and temperature in China are studied,based on the NCEP/NCAR reanalysis data and precipitation and temperature data in China from 1968 to 2008. The results reveal that the main anomalous center of atmospheric kinetic energy in winter lies in the region of East Asia Westerly Jet. The kinetic energy in aforementioned anomalous centers shows remarkably interannual and interdecadal variations. In winter, the reducing (increasing) of the atmospheric kinetic energy in the region from the central-eastern part of China to the northwestern Pacific is closely related with the weakening (intensification) of East Asian Westerly Jet, and finally causes more (less) precipitation in eastern China and higher (lower) temperature in northeastern China. The increasing (reducing) of the atmospheric kinetic energy in the southwestern side of Qinghai-Tibet Plateau is closely related with the intensification (weakening) of South Asian Westerly Jet, and finally causes more (less) precipitation in southeastern China and lower (higher) temperature in Guangxi, Guizhou, and Sichuan Province. In winter, the variation of the Asian atmospheric kinetic energy mainly causes the variation of Asian Westerly Jet, which in turn may cause the anomalous winter climate in China.