上海地区大气气溶胶光学厚度的遥感监测

Monitoring Atmospheric Aerosol Optical Depth in Shanghai Using Remote Sensor Data

采用V5.2算法,以MODIS 1B数据为数据源,利用Matlab软件进行数据预处理,反演了上海地区大气气溶胶光学厚度(AOD).将AOD反演值分别与NASA的MOD04-L2气溶胶产品(10 km×10 km)以及CE-318太阳光度计实测结果进行对比.结果表明:V5.2算法与NASA气溶胶产品相比,其精度更好,分辨率更高.基于V5.2算法和利用MODIS遥感影像反演结果,分析了上海市典型天气AOD;同时,将反演值与城市空气污染指数(API)进行了对比.结果表明:AOD从一定程度上可以反映地面大气污染状况.上海2008年AOD12月最小,大气相对较清洁,6月最大,大气相对较浑浊;AOD的日际变化呈早晚高、中午略低的趋势,其中每日的09:00和18:00出现全天最高值,12:00左右也会出现小高峰.

The aerosol optical depth（AOD） of the Shanghai urban region was obtained using the V5.2 algorithm from MODIS level 1 B data.First,the data was preprocessed with Matlab software.The results obtained by this method were respectively compared to AOD from CE-318 automatic sun-photometer observation and MOD04-L2 aerosol products（10 km×10 km） from NASA in this area.The results indicated that this method had better accuracy and higher spatial resolution.Based on the obtained results by this method and from MODIS remote sensing images,the AOD of typical weather in Shanghai was analyzed.The Air Pollution Index（API） of Shanghai and the obtained results were also compared and analyzed.The results showed that AOD had relevance with API,and could reflect the atmospheric pollution condition to a certain extent.The monthly variation characteristics of AOD in Shanghai in 2008 had a minimum value in December with relatively clean atmosphere,and maximum value in June with relatively thick atmosphere.AOD varied diurnally,being high in the morning and evening and low at noon,with maximums at 09：00 and 18：00,and another smaller peak value at 12：00.