The Characteristics Of Anthropogenic Emission Areas And Adjacent Ocean Clouds And Their Responses To Aerosols Are Studied Using Satellite Data

Clouds and cloud-aerosol interactions have important and complex effects on the radiative transfer of the earth and are the main source of uncertainty for studying climate change.In this paper,we used the Level-2 cloud classification product data(combined with CALIPSO satellite which has the aerosol lidar)2B-CLDCLASS-LIDAR provided by the Cloudsat satellite and MODIS data MYD08?D3 which are both belonging to the A-Train satellite train.A total of 8years of sample data from March 2007 to February 2010 and March 2013 to February 2016 were employed for statistical analysis to study the relationship between different types of monolayer clouds and aerosols over major anthropogenic emission areas of the northern hemisphere(Eastern China,Eastern US,and Western Europe)and their adjacent ocean.The main conclusion are as follows:1.It can be seen from the spatial distribution of the occurrence frequency of different cloud types that the spatial distribution of the occurrence frequency of clouds can be as high as 90%for cirrus and stratocumulus,about 70% to 80% for altostratus,and nearly 70% for altocumulus and cumulus,while only nearly 20% for deep convective clouds and stratus.Among them,cirrus,deep convective clouds and cumulus are mostly found in low-latitude marine areas.Altostratus and altocumulus are mostly found in mid-low latitudes land areas where are industrially developed.Stratocumulus and stratus and nimbostratus are mostly found in midhigh latitudes,and stratocumulus and stratus mostly occurred in marine areas,but nimbostratus mostly occurred in land areas.2.The frequency of different cloud types in different seasons is obviously different.The occurrence of clouds in spring and autumn is relatively less.In summer,cloud types occurring most are mainly cirrus,deep convective clouds,cumulus and stratus.And the stable cloud types,such as altostratus and stratocumulus and nimbostratus,dominate in winter.The frequency of occurrence of different cloud types is different in each region,but the total occurrence frequency of cirrus,stratocumulus and cumulus is as high as 50% to 70%,followed by altostratus,altocumulus and nimbostratus.While the two types of clouds,deep convective clouds and stratus,account for less than 10%.By studying the average monthly change characteristics of the occurrence frequency of each cloud type,it is found that the monthly changes in the occurrence frequency of cirrus and stratocumulus are opposite,while the monthly changes in the occurrence frequency of altostratus and nimbostratus are similar.3.The analysis results between different cloud types and aerosol trend changes have obvious sea and land differences.The correlation between them is good in the land area,but the correlation in the adjacent ocean area is very poor.Generally,the occurrence frequency of cirrus,altocumulus,cumulus and deep convective clouds is positively correlated with the variation trend of AOD,while the occurrence frequency of altostratus,stratocumulus(including stratus)and nimbostratus are negatively correlated with the variation trend of AOD.In addition,in the EU-EUO region and WE-WEO region,the correlation between the change trend of cloud types and AOD is relatively good,while the correlation in the EC-ECO region is poor or even opposite.