Study on Accuracy Evaluation of MODIS AOD Products and Spatio-Temporal Distribution Characteristics of AOD in Hangzhou

Abstract

In recent years, although the quality of the atmospheric environment has improved in some regions, monitoring air quality remains crucial. Aerosol optical thickness (aerosol optical depth, AOD) reflects the attenuation effect of atmospheric aerosol on light, which is an important parameter in aerosol research and plays an important role in the study of the atmosphere. Based on the CE-318 photometer data of 2015, 2016, and 2020 in Hangzhou and the MODIS satellite AOD data of 2015, 2016, and 2020, this paper first obtains the correlation between the MODIS AOD data and the ground-measured data by linear fitting. Then, the spatial and temporal distribution of the MODIS AOD data from 2012 to 2020 is analyzed. The analysis results indicate that the average correlation coefficient between the MODIS AOD data and ground-measured data is 0.77, and the average relative error is 30.53%. Thus, the MODIS AOD data can be used as an important basis for atmospheric research in Hangzhou. Based on this, the conclusions are as follows: (1) the AOD value in Hangzhou has been decreasing in recent years, from 0.43 in 2012 to 0.28 in 2020, with an average annual decrease of 0.017. (2) The AOD value in Hangzhou is large in spring and summer, and small in autumn and winter, with an average AOD value of 0.45 in spring, 0.39 in summer, 0.30 in autumn, and 0.33 in winter. (3) The AOD value in Hangzhou is large in the east and small in the west, and the AOD values in the Hangzhou urban area, Xiaoshan, and Yuhang are higher.