我国硫酸盐气溶胶气候效应的数值模拟-气象研究与应用

文章信息/Info

Title:: A numerical study of sulfate aerosol direct effect and its impact on the East Asia climate

Author(s):: LI YANG; SONG JUAN; SUN LEI; Jiangsu Institute of Meteorological Sciences, Nanjing 210009, China

Keywords:: RegCM3; Sulfate Aerosol; Direct Radiative Forcing; Climate Effects

摘要:: 气溶胶的气候效应近年来备受关注。区域气候模式能够在有限的计算资源下取得更高的分辨率,成为一种研究区域气候的有力工具。本文使用意大利国际理论物理中心(ICTP)开发的区域气候模式(RegCM3),对2008年12月~2009年11月我国硫酸盐气溶胶的时空分布及其直接气候效应进行了模拟。研究表明受大气环流影响,硫酸盐气溶胶空间分布在夏季分布最广,而其最大平均季度柱浓度出现在四川盆地,达到了27mg·m^-2。受特殊地形的影响,四川盆地上空在全年一直维持着高浓度的硫酸盐。硫酸盐气溶胶对直接辐射强迫与其柱浓度的分布有很好的相关性。直接辐射强迫在夏季分布最广,其数值达到了-2.99W·m^-2,全年平均为-2.4W·m^-2。硫酸盐的直接气候效应造成了地面气温下降,在夏季达到了-0.26℃,全年平均为-0.09℃。直接气候效应对降水总体表现为微弱的抑制作用,但不同区域,不同季节差异较大。

Abstract:: The climate effects of aerosol have dragged more and more attention in recently years. For achieving higher resolution under the limited calculated resource, the regional climate models become a robust tool of studying the issue. The RegCM3, which is developed by the ICTP, is used in this study. With the model, we focused on the sulfate aerosol spatial distribution and its direct radiative effect and the effects on East Asia with the domain of Chinese mainland from December 2008 to November 2009. The simulated results show that there are the high concentration of sulfate aerosol in Sichuan basin, middle and east China. Affecting by the terrain, Sichuan basin always has a high sulfate concentration, which can be as high as 27mg m^-2 in the autumn. The direct radiative forcing presents a well relativity with the sulfate loading. The radiative forcing has a maximum value of-2.99 W·m^-2 in summer and the yearly average direct radiative forcing at the tropopause due to sulfate aerosol is-2.40 W·m^-2, which lead to a cooling effect on the surface and slightly restraining the precipitation. Although the tendency of the temperature and precipitation was the same on the whole region of China, it has significant diversity in difference areas and seasons.