Analysis of aerosol characteristics over the China Sea by MODIS data

摘要

MODIS Collection005 aerosol product is validated by a new method over the China Sea. We use aerosol optical at 550nm(A0T550) and fine mode fraction(FMF) in its aerosol product to analyze the spatial distribution and season variation of aerosol over the China Sea. Then meteorological data will be used to discuss the reason of aerosol characteristics. The results show that firstly MODIS Collection005 aerosol product has a good quality over the China Sea and it is better than MODIS Collection004 data over the China Sea. Secondly, AOT550 and FMF have a notable season variation influenced by the meteorological condition and the transport from continental source. AOT550 reaches the largest value in spring and winter, and it reaches the least value in summer and fall; oppositely, FMF reaches the largest value in summer and fall, and it reaches the least value in spring and winter. In the third, AOT550 and FMF have marked longitudinal variation. AOT550 appear the maximum value between 30°N-40°N and decrease towards to north and south. Meanwhile, FMF increase from south to north and the tendency of the increase became slow at 30°N. And they have an obvious meridional variation. AOT550 and FMF both decrease with the increase of longitude, which suggest that anthropogenic aerosol have an important role over the China Sea. Finally, based on seven years meteorological data, the reason of the aerosol characteristics over the China Sea are discussed. Wind and rainfall are the two important factors.