基于CloudSat/CALIPSO资料的我国北方2个区域云垂直分布差异研究

The vertical distribution of cloud properties in two regions of northern China based on CloudSat/CALIPSO data

选用2008年1月—2014年10月的Cloud Sat/CALIPSO卫星资料,对中国北方两个4°×4°区域云垂直结构及其微物理参量进行了对比研究,区域1(114~118°E,37.5~41.5°N)和区域2(110°E^114°E,37.5~41.5°N)纬度相同经度不同。结果表明:1)区域1(E1)和区域2(E2)暖云层、混合云层和冷云层的云出现概率(Cloud Occurrence Probability,COP)差别较大。E1暖云层COP春季最大,E2则在夏、秋季达到较大值;E1混合层COP最大值出现在冬季,E2则出现在春季;2个区域冷云层COP均在春季达到最大。2)2个区域的COP高值区厚度有明显的季节性差异,E1的COP高值主要出现在夏、冬季,E2则主要出现在春、夏季。E1秋、冬季云体雷达回波最大值强于E2,但春、夏季弱于区域1。3)E2在春、秋季的液水含量、冰水含量、云滴有效半径均高于E1。

The cloud vertical structure directly affect the atmospheric heating rate and exert great influence on atmospheric radiation and circulation.This paper focused on investigating the difference of the cloud vertical properties over two4°×4°adjacent regions centered at(395°N,116°E)as E1region and at(395°N,112°E)as E2in North China.The CloudSat2B products and the DARDAR products from Cloud Aerosol Water Radiation Interactions(ICARE)from January2008to October2014were used to give a statistical analysis on the distribution characteristics of the cloud vertical structures and cloud microphysical parameters.The CALIPSO level2products from June2006to September2008were used to analyze the statistical distribution characteristics of the cloud vertical structures.The latitudes of the two regions are different but the longitude ranges are the same.E1is centered in the Jing Jin Ji metropolis circle where the atmospheric environment such as aerosol pollution levels and humidity conditions are different from that in E2.To investigate the impacts of aerosols on cloud distributions and other properties in different atmospheric environments,the two adjacent regions were selected and compared in terms of the distribution characteristics of the clouds in different temperatures which can reflect the cloud droplet phase.The statistical results show that:1)The cloud structures of the two regions are obviously disparate in the mixed cloud layer(-40-0℃),warm cloud layer(>0℃)and ice cloud layer(<-40℃).The largest value of the cloud occurrence probability(COP)in E1in the warm cloud layers appear in spring,which is43times of that in E2,and the largest one in E2appears in autumn,which is46times of that in E1.The COP in the mixed cloud layers in E1reaches the maximum in winter and in spring in E2with71%and83%respectively.The COP in the ice cloud layers in E1and E2both reach maximum in spring with29%and16%.2)There are obvious differences in seasons for the layer thicknesses of the COPs with high values.The layers with large COPs mainly appear in spring and winter in E1or spring and summer in E2.The higher the height is,the smaller value of the reflectivity with higher cops.The largest reflectivity in E1is stronger than that in E2in autumn and winter.3)The liquid water content(LWC),liquid effective radius(LRE),ice effective radius(IRE)and ice water content(IWC)in E2are larger than those in E1,which is closely related to the stronger aerosol loading in E1.The statistical characteristics show that the interaction between aerosols and clouds has a complex feedback effect on the changes and liquid water content.The research results from the present study are expected to provide the knowledge that is needed for parameterizing cloud formation in climate models.