摘要
本文利用发展的RIEMS对硫酸盐气溶胶第一间接辐射强迫及其气候效应进行了研究。同卫星观测和其它模式模拟结果对比表明,RIEMS能比较好地模拟云和辐射过程。东亚地区硫酸盐气溶胶的第一间接辐射强迫为负并有明显的季节变化,各季节分别为:冬季-0.88W/m2,春季-2.27W/m2,夏季-2.41W/m2,秋季-1.47W/m2,年平均为-1.75W/m2。云滴有效半径空间分布与MODIS有一致性,都表现出海洋(6~15μm)大于陆地(4~10μm),从中国东南地区向西北地区递减的趋势,但模拟结果总体上小于MODIS反演结果。硫酸盐气溶胶的间接辐射效应总体上使地表温度降低,夏季和秋季平均降温幅度在重庆市及周边地区最大可达1.5℃。水汽在冬春季由于地表温度降低主要表现为减少,夏秋季由于水汽输送变得复杂,其变化也表现得复杂,既有增加也有减少。降水的变化与水汽变化相似,冬春季中国东部大部分地区降水减少(0~60mm),冬季为0~30mm,而夏季和秋季降水变化比较复杂,夏季在四川盆地、长江中下游地区和长江以南大部分地区,降水是增加的(0~150mm),而东北大部、华北部分地区的降水是减少的(0~90mm)。硫酸盐间接气候效应的分区平均显示,除了夏季东北地区是增温(0.2℃),其他分区平均都是降温,最大降温出现在秋季华中地区,可达0.5℃。各区域冬季降水变化最小(-0.1~0cm),夏季降水变化最大,其中东北地区区域平均累积降水减少可达1.7cm,而华中地区平均降水增加了约0.2cm。
The first indirect radiative forcing and climatic effect of sulfate are investigated by using a Regional Integrated Environment Modeling System(RIEMS).The RIEMS can generally represent cloud and radiation processes by comparison with the MODIS data and the results from other models.The first indirect radiative forcing of sulfate over East Asia is negative and varies seasonally,with seasonal means being -0.88 W/m2 in winter,-2.27 W/m2 in spring,-2.41 W/m2 in summer,-1.47 W/m2 in autumn,and annual mean being -1.75 W/m2.The spatial distributions of simulated cloud droplet effective radius are similar to the MODIS data,showing larger effective radius over the sea(6-15 μm) than that over land(4-10 μm),and the decreasing trend from Southeast China to Northwest China,but the model results are systemically smaller than the MODIS data.The indirect radiative effect of sulfate generally leads to a decrease in the ground temperature,with maximum surface cooling reaching 1.5℃ in Chongqing and its vicinity in spring and autumn.The vapor decreases in winter and spring due to the ground temperature decreasing,but its changes seem much more complex in summer and fall,not only decreasing but also increasing,because the vapor transport is more complex.The changes in precipitation are consistent with those in water vapor,and show a general decrease trend over eastern China.The precipitation decreases in spring and winter over most areas of eastern China(0-60 mm),but the situation is complex in summer and autumn.In summer,the precipitation increases in the Sichuan Basin,the middle and lower reaches of the Yangtze River,and large areas south of the Yangtze River(0-150 mm),whereas in most areas of Northeast China and the North China Plain,the precipitation decreases(0-90 mm).The spatial averages of these changes over specific regions of China show that the ground temperature decreases in all regions and all seasons except Northeast China in summer where the ground temperature increases(0.2℃),the maximum decrease in the ground temperature appears in the region of Central China(as large as 0.5℃) in autumn.The changes in precipitation in these regions are smallest in winter(-0.1-0 cm),largest in summer.In summer,the decrease in regional mean accumulated precipitation can reach 1.7 cm in Northeast China,whereas the precipitation increases by about 0.2 cm in the region of Central China.
出处
《大气科学》
CSCD
北大核心
2011年第3期547-559,共13页
Chinese Journal of Atmospheric Sciences
基金
中国科学院知识创新工程重要方向项目KZCX2-YW-Q11-03
气象行业科研专项GYHY200906020
关键词
硫酸盐
间接辐射强迫
气候效应
数值模拟
东亚地区
sulfate
indirect radiative forcing
climatic effect
numerical simulation
East Asia