青藏高原季风对我国西北干旱区气候的影响

The Effect of Tibetan Plateau Monsoon on the Climate in the Arid Area of Northwest China

基于ERA-Interim逐月再分析资料及同期高原和我国西北干旱区观测站温度与降水资料,分析高原季风与西北干旱区气候的关系,对比高原典型强弱季风年平均大尺度环流和水汽输送条件的差异,探讨高原强弱季风年西北干旱区气候差异形成的原因。研究结果表明:高原季风与我国西北干旱区气候相关关系显著;高原强弱季风年对应的大尺度环流和垂直环流系统存在明显差异;水汽条件和抬升条件好坏与降水量多寡配合得较好,即强高原季风年,高原北部边缘水汽条件和抬升条件更有利于降水,而弱高原季风年,高原北部边缘水汽条件和抬升条件偏差,对应降水量较常年同期偏少。

Based on monthly mean ERA-Interim reanalysis data and the temperature and precipitation data in the arid area of Northwest China during 1979-2013, differences in climate in the arid area of Northwest China between strong and weak monsoon years are analyzed. Correlation between the plateau monsoon and climate in the arid area of Northwest China is quantified. The mean large-scale circulation and water vapor transport are compared between strong and weak plateau monsoon years. The results show that the correlation between the plateau monsoon and climate in the arid area of Northwest China is significant. There are obvious differences in large scale circulation and vertical circulation system between the strong and weak monsoon years. The water vapor condition and uplifting condition are in good agreement with precipitation. The ability of water vapor uplifting along the northern flank of the Plateau is one of the important factors affecting climate in the arid area of Northwest China.