南海北部气溶胶光学厚度观测研究

Measurement and study of aerosol optical depth over northern South China Sea

利用2004年南海北部开放航次全程使用多波段太阳光度计观测获得的气溶胶光学厚度资料,对南海北部气溶胶光学厚度(AOD)的时空分布特征、气溶胶类型和来源等进行了分析。结果显示,近岸海域AOD值大,基本在0.5(500nm)以上,远离大陆的区域AOD值小,基本在0.2(500nm)以下。AOD值与污染源区工业生产水平和气流输送密切相关,受珠三角地区工业高度发展和冷空气南下的影响,在珠江口南部出现AOD高值中心;由于受台湾西南部工业区和东北信风的影响,台湾岛西南部海域AOD值偏大。3天的个例分析显示,海洋上空的AOD值上午和下午略高,中午最小,AOD与大气水汽含量呈正相关。ngstr m波长指数分析显示,大陆沿海海域气溶胶以小粒子为主,远离大陆海域以海盐粒子为主。

Observation data of aerosol optical depth （AOD） were obtained with sunphotometer from September 17, 2004 to October 4,2004 to discuss the temporal and spacial distributions of AOD, and the type and source of the aerosol particulate over the northern South China Sea. The results showed that AOD was generally above 0.5 （500nm） in the coastal areas, while it was below 0. 2 （500nm） in the central area of the South China Sea. AOD was closely related to the development of pollution source zone and wind transportation. The analysis of three cases showed that the minimum AOD value over sea appeared at noon during a day, and AOD was correlated to water vapor. Simulated Angstrom wavelength exponent showed that the radius of aerosol particles was small in the coastal areas and large in the central area of the South China Sea.