利用卫星数据反演中国近海气溶胶浓度及干沉降通量

Retrieving Aerosol Concentration and Dry Deposition Flux over Coastal Seas of China Using Satellite Data

利用Aqua卫星MODIS光谱成像仪遥感的气溶胶光学厚度(AOD)资料,结合CALIPSO卫星给出的气溶胶消光系数和相对湿度垂直剖面数据,反演了中国近海低层大气气溶胶浓度,并依据水面干沉降模型估算中国近海气溶胶干沉降通量的时空分布,提出了一种订正AOD的方法;使用中国沿海城市气溶胶浓度监测值,在渤海、黄海、东海和南海4个海区拟合得到了4组AOD与PM10质量浓度的线性关系;反演了2014年3月—2015年2月中国近海气溶胶浓度。结果显示,中国近海气溶胶浓度全年均值为38.15μg/m3,渤海比南海高约149%,沿岸海域高出远海约30%,冬春月份高于夏秋月份约3.7%;气溶胶干沉降通量年均值为0.028g·m-2·d-1,同样表现出北部海域高于南部海域、冬春季高于夏秋季的分布趋势。

Aerosol concentration of lower atmosphere over coastal seas of China was retrieved using Aerosol Optical Depth （AOD） data from MODIS sensor onboard Aqua satellite, cooperated with extinction coefficient and relative humidity profiles from CALIPSO satellite. Aerosol dry deposition flux over coastal seas of China was then estimated based on the retrievals and dry deposition estimation model. An AOD modification method was proposed in this study, and four aerosol retrieval models, through the incorporation of aerosol monitoring data of coastal cities of China, were established for Bohai Sea, Yellow Sea, East China Sea and South China Sea. The results show that annual mean aerosol concentration of coastal seas of China was 38.15 μg/m3 during March, 2014 to February, 2015. Aerosol concentration was approximately 149% higher over Bohai Sea than over the South China Sea, 30% higher over coastal seas than over remote seas, and 3.7% higher in winter and spring than summer and autumn. Annual mean aerosol dry deposition flux was 0.028 g·m^-2·d^-1. Consistent with the characteristics depicted in aerosol concentration, aerosol deposition flux also appeared to be higher in northern seas than in southern seas, in winter and spring than in summer and autumn.