卫星遥感中国海域气溶胶特征分析

利用AERONET地基观测,验证MODIS Collection5(MODIS_C005)气溶胶产品在中国海域的适用性。利用其550nm气溶胶光学厚度(AOT550)和小颗粒比例(Fine Mode Fraction,FMF)对中国海域气溶胶分布进行分析,结合气象场对其形成机制进行探讨,结果表明:首先,MODIS_C005气溶胶产品在中国海域有很高精度,适用中国海域;其次,中国海域AOT550与FMF存在明显的时空分布特征。时间上,AOT550在冬、春季最大,在夏、秋季最小;FMF在夏、秋季最大,冬、春季最小。空间上,在经向上,AOT550在30°N—40°N达到最大,向南北递减;FMF从南向北逐渐增加,到达30?N附近后增加减弱。在纬向上,AOT550和FMF随着经度的增加而减小;最后,中国海域气溶胶主要来自于陆源气溶胶,借助风场传输到达中国海域,同时还受到降雨的影响。

Analysis of aerosol characteristics over the China Sea by remote sensing

MODIS Collection 005(MODIS_C005) aerosol product is validated over the China Sea. Aerosol optical thickness at 550nm (AOT550) and fine mode fraction (FMF) are used to analyze spatial-temporal distribution of aerosol over the China Sea. Then meteorological data are used to discuss formation mechanism of aerosol characteristics. The results show that firstly MOD1SC005 aerosol product has a good quality over the China Sea. Secondly,AOT550 and FMF have a notable spatial-temporal distribution feature. AOT550 reaches maximum in spring and winter,and minimum in summer and fall; oppositely,FMF reaches maximum in summer and fall,and minimum in spring and winter. Meanwhile,AOT550 and FMF have marked longitudinal variation. AOT550 appears maximum between 30°N-40°N and decreases towards north and south. And FMF increases from south to north and the tendency of increase becomes slow at 30°N. In addition,they have an obvious meridional variation. AOT550 and FMF both decrease with the increase of longitude. Finally,based on meteorological data,the source is the continent aerosol and wind and rainfall are the two most important factors.