基于卫星遥感资料监测地面细颗粒物的敏感性分析

分析了垂直分布、粒径分布和吸湿增长3个影响因子及其组合对基于卫星遥感资料监测地面细颗粒物(PM2.5)的敏感性.以广州地区为例,使用影响因子及其组合对2010年全年、干季和湿季的MODIS气溶胶光学厚度(AOD)资料进行订正,与时空匹配的地基实测PM2.5质量浓度数据对比和分析.研究表明,两者的直接相关性很低,全年相关系数(R)仅有0.147.经单个因子订正后,效果提升有限.其中,粒径因子的敏感性最高,垂直因子次之.组合因子中,垂直及粒径订正的效果最好,敏感性最高,全年R达0.526.垂直及粒径因子再加上湿度因子后,全年R降为0.498.垂直及湿度订正的敏感性最低,全年R仅为0.145.总体而言,垂直及粒径订正因子敏感性最高,效果最佳.粒径因子加入后订正效果提升显著,而经验吸湿增长因子的时空代表性比较单一.

Analysis of sensitivity of monitored ground PM2.5 concentrations based on satellite remote sensing data

The sensitivities of vertical distribution, particle size distribution and hygroscopic growth, which are factors of influencing in monitoring ground PM2.5 concentrations, were analyzed in this study based on satellite remote sensing data. MODIS AOD (aerosol optical depth) corrected by these factors were compared with synchronous ground PM2.5 concentration measurements during the dry and wet season of 2010 and all the year round in Guangzhou. The results indicated that initial correlations between AOD and PM2.5 concentrations are very low and the correlation coefficient (R) of the year is only 0.147. There are limited improvements if it is only corrected by single factors. Among them, size-corrected factor has the highest sensitivity, followed by vertical-corrected factor. Vertical and size-corrected factor has highest correction effect among the combined factors and the R of the year is up to 0.526. The R of the year reduces to 0.498by the vertical-size and RH-corrected method. The vertical and RH-corrected factor has lowest correction effect and the R of the year is only 0.145. Overall, the vertical and size-corrected factor has the highest sensitivity and the best effect. The correction effect enhances significantly by added size factor. Experimentally, the hygroscopic growth factor has simple representation of space and time.