青藏高原热状况对夏季西南地区气候影响的分析及模拟

Analysis and Simulation Study on the Influence of Heat Condition over Qinghai-Xizang Plateau on Climate over South-West China

应用诊断和数值模拟方法,研究了青藏高原热状况的特征及其对西南地区环流和降水等的影响。结果表明:青藏高原热源有不同的表征方法,它们相互联系、相互制约;冬季青藏高原测站温度与西南地区降水有着同期和滞后的相关关系,它的强弱对川渝等地降水有指示意义。高原测站温度呈上升趋势,这可能是造成四川盆地平均气温从20世纪中叶以来呈下降趋势的原因之一。同时,青藏高原热源强迫是大气环流系统形成和维持的重要原因,这种热源强迫有利于对流层低层气旋环流或低涡的生成、发展,也有利于季风环流增强,是造成青藏高原及周围地区以及高原东侧大范围降水变化的原因。

Based on the diagnosis and simulation methods, the characteristics of the heat condition over QinghaiXizang Plateau(QXP) and its influences on the circulation and precipitation in the region of southwestern have been studied. It is shown that there are different showing methods of the heat condition over QXP which have relationship and restriction between each other. In winter, there are the same period and lag correlations between the precipitation of southwestern China and the heat condition of the Plateau. The growing thermal over Plateau may be one of the reasons why the average temperature in Sichuan basin became somewhat cooling during the middle last century. At the same time, the heat source play an important role in the forming and maintaining of the atmosphere circilation. And possibily it is the main reason of causing the changes of rainfall over QXP and its sourroundings.