基于Himawari-8的气溶胶反演研究

为获取中国区域高时空分辨率、高精度的气溶胶光学厚度（AOD）产品。基于Himawari-8卫星数据和MODIS地表反射率产品，反演了中国区域2018年4月~2019年4月逐10分钟的AOD，该方法可同时对暗像元、亮像元区域进行反演。依托全球气溶胶观测网（AERONET）中国境内的6个观测站数据，对反演结果进行一致性检验，同时将AOD反演结果与Himawari-8官方最新发布的AOD产品（020版）进行对比。结果表明：①红蓝比值法AOD反演结果与AERONET AOD之间相关性很高，除包头站外，其余5个站点的相关系数R在0.728~0.863之间，EE（误差期望）范围内样本点百分比在47.7%~68.6%之间，与Himawari-8 AOD产品相比有很大优势;②红蓝比值法AOD反演结果与AERONET AOD在时间序列走势上基本一致，但在AOD >1时，反演结果较AERONET AOD偏高。Himawari-8 AOD春夏季走势相对于AERONET AOD较为一致，但由于秋冬季Himawari-8 AOD有明显的日变化，且日变化较大，其走势与AERONET AOD偏离较大;③红蓝比值法AOD反演结果与MODIS AOD产品空间分布基本一致，AOD反演结果总体较MODIS AOD略为偏低。在冬季时红蓝比值法反演范围较MOD04_3K AOD的反演范围广;④红蓝比值法AOD在冬春季的北方高反射率地表区域的反演结果精度和反演范围较Himawari-8 AOD产品和MOD04_3K产品有很大优势。

Retrieval of Aerosol Optical Depth based on Himawari-8

To obtain Aerosol Optical Depth (AOD) products with high spatial and temporal resolution and high precision in China. We enhance the AOD retrieval algorithm by applying the MODIS red and blue surface re?ectance ratio database in the algorithm. The enhanced algorithm is able to retrieve AOD over both dark and bright surfaces., we retrieve the 10-minute AOD of China from April 2018 to April 2019. The AOD retrievals from the enhanced red-blue ratio algorithm (RB AOD) were validated by the Level 1.5 AERONET (Aerosol Robotic Network) sunphotometer measurements and MOD04_3K AOD , and the retrieval of AOD were compared with the latest AOD product (version 020) released by Himawari-8.The results show that :(1) The AOD retrievals from the enhanced algorithm agreed well with those from the AERONET. Except Baotou station, the correlation coefficient R of the other five stations is between 0.728-0.863, and the percentage of sample points within the range of EE (Expectation of Error) is between 47.7% and 68.6%, which has great advantages over Himawari-8 AOD products.(2) The RB AOD are basically consistent with AERONET AOD in time series trend. the RB AOD results are higher than those of AERONET AOD when AOD > 1.The spring and summer trend of Himawari-8 AOD is relatively consistent with that of AERONET AOD. However, due to the obvious diurnal change of Himawari-8 AOD in autumn and winter, and the diurnal change is relatively large, its trend deviates greatly from AERONET AOD.(3) The spatial distribution of RB AOD is basically consistent with that of MODIS AOD products, and the retrieved results are slightly lower than those of MODIS AOD.In winter, the inversion range of red-blue ratio method is wider than that of MOD04_3K AOD.(4) the red-blue ratio retrieval algorithm has great advantages over Himawari-8 AOD and MOD04_3K in precision and range of retrieval results of high-reflectance surface area in north China in winter and spring.