“…In total, the correlation between estimated and measured PM 2.5 concentration is more higher in spring and autumn. The In our study, even though the complicated PM 2.5 concentration distribution in Beijing, the modified corrected AOD-PM 2.5 models achieved higher model fitting R 2 values than those in previous studies, e.g., an observation-based algorithm that considers the effect of the main aerosol characteristics applied to the Beijing-Tianjin-Hebei region with R 2 of 0.70 [3], the GWR model applied to the whole China mainland with an overall R 2 of 0.64 [5], an improved model applied to the Beijing-Tianjin-Hebei region with an R 2 of 0.77 [15], satellite-driven PM 2.5 models with VIIRS nighttime data applied to the Beijing-Tianjin-Hebei region with R 2 of 0.75 [19], and NAQPMS data incorporated to MODIS data applied to the Beijing-Tianjin-Hebei region from January to December 2017 with seasonal R 2 values of 0.75, 0.62, 0.80, and 0.78 in the spring, summer, autumn, and winter, respectively [22]. Table 3 is comparison between estimated and measured seasonal average PM 2.5 concentration of 15 monitoring stations from 2014 to 2016.…”