北疆地区MODIS 3km气溶胶光学厚度与PM10质量浓度的相关性分析

利用2016年MODIS 3 km分辨率的气溶胶光学厚度(AOD)日产品、PM_(10)质量浓度以及相关气象数据,开展了北疆地区AOD与PM_(10)质量浓度的相关性分析.结果表明,AOD与PM_(10)质量浓度的直接相关程度较低,相关系数仅为0.294.对比分析了利用能见度数据对AOD进行垂直订正,然后再用相对湿度数据对其进行二次订正(AOD垂直-湿度订正)和利用能见度数据对AOD进行垂直订正和相对湿度数据对PM_(10)质量浓度进行订正(AOD垂直订正-PM_(10)湿度订正)两种订正方法,结果指出"AOD垂直订正-PM_(10)湿度订正"可显著提高二者之间的相关性.订正之后,北疆地区AOD与PM_(10)质量浓度的相关系数达到0.755,呈显著正相关;阿勒泰的订正效果最好,相关系数为0.837.最后,基于垂直订正后的AOD和湿度订正后PM_(10)建立两者之间的最优拟合模型,并利用新建的模型反演了北疆地区PM_(10)质量浓度.反演得到的PM_(10)质量浓度与经过湿度订正后PM_(10)呈显著正相关,相关系数为0.688;昌吉和伊宁的反演效果最好,相关系数分别为0.910和0.829.本研究结果表明MODIS 3 km AOD产品经过垂直和湿度订正后,可作为北疆地区监测PM_(10)质量浓度的一个有效手段.

A correlation analysis of MODIS 3 km aerosol optical depth and PM10 concentration in Northern Xinjiang

A correlation analysis of MODIS 3 km Aerosol Optical Depth (AOD) and PM₁₀ concentration has been performed over Northern Xinjiang Uygur Autonomous Region with the MODIS products, PM₁₀ concentration datasets, and related meteorological data in 2016. The results indicate that there is a low direct correlation between AOD and PM₁₀ concentration with the correlation coefficient of 0.294. Therefore, two methods are utilized to correct the AOD and PM₁₀ concentration, and a comparison between them has been accomplished. One is AOD vertical correction with visibility at first, and then a further correction is made with humidity (named as "AOD vertical-humidity correction"). The other is AOD vertical correction with visibility and PM₁₀ concentration correction with humidity ("AOD vertical-PM₁₀ humidity correction"). It is revealed that the correlation between AOD and PM₁₀ concentration has been greatly improved with the correlation coefficient of 0.755, after AOD vertical correction with visibility data and PM₁₀ concentration correction with humidity over Northern Xinjiang. Among all the stations, the largest correction coefficient of 0.837 appears at Aletai station. Finally, an optimal fitting model has been established by using the vertical corrected AOD and humidity corrected PM₁₀ concentration. Based on the model, PM₁₀ concentration is retrieved in Northern Xinjiang with the MODIS 3 km Aerosol Optical Depth (AOD) as inputs. The retrieved PM₁₀ concentration has a positive correlation with the humidity corrected PM₁₀ concentration with the correlation coefficient up to 0.688.The two largest correlation coefficient are 0.910 and 0.829 occurs at Changji and Yining stations, respectively. This study proposes that MODIS 3 km AOD products with vertical and humidity corrections are effective to monitor PM₁₀ concentration in Northern Xinjiang.