东亚单层低云特性及其短波辐射强迫的季节变化

利用云与地球辐射能量系统CERES(clouds and the earth’s radiant energy system)资料,对2003-2016年东亚不同区域单层低云物理属性及地面短波辐射强迫的季节时空分布特征进行研究。结果表明:①在空间分布上,辐射强迫与单层低云量在春秋两季有着较好的相似性,而与冰/液态水柱含量在春、夏、秋三个季节有着较好的一致性。②在时间变化上,北方地区夏季的单层低云对短波辐射的削弱作用是最强的;南方地区和西北地区最强的削弱作用发生在春季;东部海域则发生在冬季。在空间分布上,春、秋、冬季最强的低云削弱效应在南方地区。夏季,东亚低云对短波辐射的削弱作用各区域都较弱,大部分区域的负辐射强迫的绝对值小于200 W·m^-2。

Seasonal Variation of Single-layer Low Cloud Physical Properties and Radiative Forcing in East Asia

The data from Clouds and the Earth’s Radiant Energy System were used to study the distribution of low-cloud physical properties and downward shortwave radiative forcing in different regions of East Asia from 2003 to 2016. The results are as follows: ① The variation of single-layer low cloud radiation forcing was similar with the single-layer low cloud fraction in spring and autumn,and there was a good consistency with the ice/liquid water path in spring,summer and autumn;② Temporally,the weakening effect of single-layer low cloud on shortwave radiation was the strongest in the north and west in summer. The strongest weakening effect in the south and northwest occurred in spring;that in the eastern ocean occurred in winter. In terms of spatial distribution,except for summer,the strongest single-layer low cloud weakening effect in other seasons occurred in the south. In summer,the singlelayer low cloud in the East Asia had a weaker effects on shortwave radiation,and the absolute value of the radiation forcing was less than 200 W·m^-2.