人为气溶胶对东亚夏季风直接气候效应的成因分析

CAUSATION ANALYSIS OF THE DIRECT CLIMATE EFFECTS OF ANTHROPOGENIC AEROSOLS ON EAST-ASIAN SUMMER MONSOON

采用耦合气溶胶模式的区域气候模式RegCM3对1988—2009年南亚和中国的人为排放气溶胶对东亚夏季风的直接气候效应影响进行数值模拟,采用合成分析、相关分析方法对其进行气候动力学诊断分析。结果显示:在气溶胶排放大值区域中,中国夏季排放最多,而南亚则是春季、冬季排放较多。总体而言,中国气溶胶柱的浓度含量高于南亚。中国境内气溶胶分布主要呈西南-东北走向,其中四川盆地附近为一高值中心。由于气溶胶负的短波辐射作用,改变了海陆气压梯度,从而对东亚夏季风的强度、分布产生一定影响,削弱了东亚夏季风在江淮以北地区的发展。同时讨论了东亚夏季风对于中国境内气溶胶大值区柱浓度含量、分布的反馈作用。

A regional climate model coupled with an aerosol model is employed to numerically simulate the direct climate effects of the anthropogenic aerosols discharged in South-Asia ＆ China in the East-Asian summer monsoon during 1988-2009. Based on the data of the numerical simulation, the composite analysis and correlation analysis are used to make diagnostic analysis of climate dynamics. Results show that the month of maximum emission of the mean column burden of the anthropogenic aerosols in the main emission areas of South Asia is opposite to that in China in phase. Summer is the season of maximum discharge amount in China, but the emission amounts are more in South-Asia in spring ＆ winter. On the whole, the mean column burden of the anthropogenic aerosols in China is relatively higher compared with that in South-Asia. The trend of distribution of aerosols is SW-NE in China, and Sichuan Basin is the emission center of aerosols. The effect of negative short wave radiative forcing alters the gradient of pressure between land and sea, weakening the development of East-Asian summer monsoon over the northern part of Yangtze-Huaihe River Basin. We also discuss the feedback effect of East-Asian summer monsoon which is changed by the anthropogenic aerosols on the concentration ＆ distribution of aerosols in China.