摘要
本文在区域气候模式RIEMS2.0中引入沙尘气溶胶的起沙机制,同时建立了与气候模式连接的沙尘气溶胶输送模式,并在辐射模块中加入沙尘气溶胶的影响,模拟沙尘气溶胶的输送、扩散、沉降等过程以及对辐射的影响.利用此模式得到了1998年春季3、4、5月中国地区沙尘气溶胶的主要源区分布、沙尘气溶胶的柱浓度分布、光学厚度等物理量及其辐射效应和气候效应.结果表明春季中国沙尘源区主要集中在内蒙古西部的腾格里沙漠、巴丹吉林沙漠,中部的浑善达克沙地,南疆塔克拉玛干沙漠东部,河西走廊地区以及青海的柴达木盆地附近,这些地区的起沙率大于5μg/(m2.s),最大为65μg/(m2.s);沙尘气溶胶柱浓度最大值达0.55 g/m2,出现在塔克拉玛干沙漠地区,相应的光学厚度最大值是0.50.沙尘气溶胶使得中国地区地面短波辐射收入平均减小了4.10 W/m2,地面长波辐射收入增大了+0.46 W/m2,地面净辐射强迫为-3.64 W/m2,大气辐射收支与地面相反,净辐射强迫为+3.10 W/m2;同时沙尘气溶胶通过影响到达地面的辐射使得地面有较强的降温,整个模拟区域平均地面气温降低了0.24 K,而北方地区地面气温降低了0.37 K;沙尘对于降水的影响主要体现在对小雨的影响上,沙尘气溶胶使得模拟区域内小雨减小了20%左右;另一方面,华北地区降水受沙尘气溶胶影响最大,总降水减少了13.8%,而全区域总降水只减少了2%.
In order to study the climate effects of the dust aerosol over China, an uplifting mechanism of dust aerosol and its transportation processes with the radiation modules was introduced into a regional climate model RIEMS2.0 （Regional Integrated Environmental Model System）. Based on the model system, the distribution of dust aerosol, its column burden and optical depth over China in March, April and May 1998 were simulated and the radiative effects of dust aerosol were detected. The results show that the main dust sources are in northwestern China, where the emission rates exceed 5 g/（m^2 · s） with a maximum up to 65 g/（m^2 · s）. The maximum dust aerosol column burden and optical depth, which were compared with Total Ozone Mapping Spectrometer （TOMS） aerosol index, are about 0.55 g/m^2 and 0.50, respectively. The regional changes in radiative flux at the surface are as large as --4.10 g/m^2 at solar and ＋0.45 W/m^2 at the thermal wavelengths in seasonal mean,and the net radiative forcing is -3.64 W/m^2. The radiative effects in the atmosphere are adverse to that of the surface and the net radiative forcing in the atmosphere is ＋3.10 W/m^2. On the other hand, the decrease Of surface temperature due to dust aerosols is 0.37 K in North China and 0.24 K in China. The drizzle is affected more by dust aerosols and the reduction is about 20%. The precipitation in North China can decrease by 13.8%, while the average decrease of China is only 2 %.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第6期598-607,共10页
Journal of Nanjing University（Natural Science）
基金
国家重点基础研究发展规划(2006CB400506)
国家自然科学基金(40775014)
关键词
沙尘气溶胶
光学厚度
气溶胶指数
辐射强迫
小雨
气候效应
dust aerosol,column burden, total ozone mapping spectrometer （TOMS） aerosol index, optical depth,radiative forcing, drizzle, climate effects
作者简介
通讯联系人，E—mail：liuhn@niu．edu．cn
