北半球对流层厚度的时空变化特征

利用1948—2010年NCEP/NCAR逐月位势高度再分析资料、美国国家海洋局提供的1948—2010年逐月海温再分析资料,分别定义了1 000—500 hPa和500—200 hPa厚度,利用EOF、SVD等方法研究了北半球对流层厚度时空演变特征及其与大气环流和海面温度的关系。结果表明,冬季平均厚度EOF第一模态均具有北太平洋及附近高纬度亚洲大陆地区与北美大陆高纬地区反位相变化的特点,而夏季第一模态则是北半球范围内较一致的位相分布;冬、夏季平均厚度EOF第二模态均突出体现了欧亚大陆及附近地区与北半球其他地区反位相变化的特点;冬、夏季厚度场的变化形势与大气环流及海面温度具有密切联系。

Temporal and spatial variations of troposphere thickness in northern hemisphere

Based on the 1948-2010 NCEP/NCAR reanalysis monthly geopotential height data and NOAA monthly SST （sea surface temperature） data, the 1 000-500 hPa and 500-200 hPa thicknesses are respectively defined as the lower and upper troposphere thicknesses. Temporal and spatial variations of the lower and upper troposphere thicknesses in Northern Hemisphere and their relationships with atmospheric circulation and sea surface temperature are analyzed by using the EOF （empirical orthogonal function） and SVD （singular value decomposition） analysis methods. Results show that for the first EOF modes of the lower and upper troposphere thicknesses, the thickness anomalies over North Pacific and its neighboring Asian high-latitude area are anti- phased to those over the high-latitude area of North American continent in winter, and the thickness anomalies are concurrent in Northern Hemisphere in summer. For the second EOF modes in winter and summer, the thickness anomalies in Eurasia are anti- phased to those in the other areas of Northern Hemisphere. The temporal and spatial variations of troposphere thickness in Northern Hemisphere have close relations with the atmospheric circulation and SST.