基于太湖地区MFRSR遥感大气气溶胶光学特性和大气污染状况

Remote sensing of aerosol optical properties and air pollution with MFRSR measurements in Taihu region

利用2008年5月16日至2009年4月17日太湖地区多光谱旋转遮光辐射仪(multi-filter rota-ting shadow-band radiometer,简称MFRSR)的观测资料进行反演,得出415、500、615、675和870nm5个波段大气气溶胶光学厚度(aerosol optical depth,简称AOD)及各季节浑浊度系数和波长指数的统计结果。结果表明,5个波段AOD的最大值分别为1.9、1.6、1.3、1.2和1.0;它们谱分布的半宽度分别为0.90、0.70、0.55、0.45和0.25;AOD频率分布极大值处所对应的AOD值分别为0.750、0.550、0.475、0.425和0.425。5个波段AOD的平均值在春季最大,夏季次之,除870nm外,均为冬季最小。浑浊度系数变化范围为0～1.25,其中大于0.2的占97%以上,大于0.4的占66%以上。春季、夏季、秋季和冬季的波长指数变化范围分别为0～3.0、0～2.8、0.2～2.0和0.2～2.0,表明太湖地区大气污染较为严重,且受人为源的影响显著。相对于秋冬季,春夏季有较大粒径的气溶胶粒子存在。

Based on the MFRSR（ multi-filter rotating shadow-band radiometer）data observed at Taihu Site during May 16,2008 to April 17,2009 ,the aerosol optical depth （AOD） is retrieved and its statis-tical results at 415 nm,500 nm,615 nm,675 nm and 870 nm are given,as well as the statistical results of turbidity coefficient and Angstrom wavelength exponent. Results indicate that the maximum value of AOD at these five wavelengths are 1.9,1.6,1.3 and 1.2, respectively ; The half width of spectrum dis-tribution are 0. 90,0. 70,0. 55,0. 45 and 0. 25, respectively;The AOD value at its frequency distribution peak are 0. 750,0. 550,0. 475,0. 425 and 0. 425, respectively. The AOD value is largest in spring, smal-ler in summer, and smallest in winter at all these five wavelengths. The Angstrom turbidity coefficients range from 0 to 1.25, with 60% data larger than 0. 4 and 97% data lager than 0. 2 ; The Angstrom wavelength exponent in spring, summer, autumn and winter are 0 to 3.0,0 to 2.8,0. 2 to 2.0, and 0. 2 to 2.0, respectively. It reflects that atmosphere is polluted occasionally and influenced remarkable by anthropogenic sources. Considering the peak distribution of wavelength exponent, it is suggested that there are larger particles existing in spring and summer than in autumn and winter.