MODIS气溶胶光学厚度在临安大气颗粒物监测中的应用

基于大气辐射传输理论的研究表明,AOD(气溶胶光学厚度)与地面PM(颗粒物)浓度(以ρ计)呈正相关. 利用2006—2010年MODIS晴空AOD数据产品与临安区域大气本底站监测的ρ(PM₁₀)进行相关分析发现,二者的R(相关系数)为0.431,直接相关程度较低. 根据AOD和气象能见度间的关系,获得了不同季节临安地区的气溶胶平均垂直标高,利用该垂直标高和RH(相对湿度)分别订正AOD和ρ(PM₁₀)后,二者的相关性(R为0.576) 明显提高.冬季AOD和ρ(PM₁₀)的相关性最好,R为0.765；夏、春季次之,R分别为0.643和0.608；秋季最低,为0.442. 经过对5年资料的对比分析,证实了MODIS气溶胶光学厚度经垂直标高和RH订正后,可用于临安地区地面空气污染的监测. 

Application of MODIS Aerosol Optical Depth in Monitoring PM10 Concentrations in Lin'an

Theoretical analysis based on atmospheric radiative transfer has indicated a positive correlation between AOD(aerosol optical depth) and surface-level PM(particulate matter) concentrations.This study was based on 5-year MODIS AOD product and PM10 concentration at Lin’an Regional Background Station,for a total of 141 data pairs.A direct correlation analysis revealed a relatively low level of relationship between AOD and PM10 concentration(R=0.431).The seasonal average aerosol scalar heights were obtained by using a formula for visibility and AOD.After correcting by the seasonal average aerosol scalar heights and the influence of relative humidity(RH),the correlation coefficient between AOD and PM10 concentration was significantly increased(R=0.576).The correlation between AOD and PM10 concentration was also dependent on season;the highest correlation coefficient was found in winter(R=0.765 after correction),while the lowest was found in autumn(R=0.442 after correction).In summer and spring,The correlation was R=0.643 and R=0.608 respectively(after correction).This study confirmed that,after taking aerosol vertical distribution and influence of RH into consideration,MODIS AOD can be used to evaluate the surface PM10 concentration in Lin’an.