A Study on Effects of Himawari-8 Based AOD Data on 3DVar of CMA-MESO/CUACE CW

Abstract

The CMA-MESO/CUACE CW is an atmospheric chemistry coupled model independently developed by China.At present， the CMA-MESO/CUACE CW 3DVar system realized the assimilation of ground-based aerosol observations of PM2.5 and PM10.In order to enhance the assimilation capability of the coupled assimilation system for non-conventional observations， based on the CMA-MESO three-dimensional variational assimilation framework of atmospheric chemical weather coupled system， the aerosol extinction coefficient is obtained by using the look-up table method.And then the observation operator， the tangent linear operator and the adjoint operator are established using the relationship between aerosol optical depth （AOD） and aerosol components.The assimilation tests were carried out for a haze process in North China on December 18 -20， 2016.The results show that after assimilating the AOD observations from the Himawari-8 satellite， the heavily polluted area of the PM2.5 is enlarged， and the analysis in southeastern Shanxi is closer to the actual situation， but the analysis of PM2.5 in the majority of the Shandong region is overestimated.The simultaneous assimilation of Himawari-8 AOD observations and ground-based aerosol concentration observations test is the best for the analysis of PM2.5， it has the highest correlation coefficients （ACCs） and the smallest mean bias， root-mean-square error and standard deviation.The PM2.5 forecast results in the heavily polluted area showed that the positive contribution of the assimilated Himawari-8 AOD observations to the PM2.5 forecasts for the >350 μg·m-3 magnitude could be sustained up to 48 h.However， the simultaneous assimilation of the Himawari-8 AOD observations and the ground-based aerosol site observations had the best test scores of PM2.5 forecasts for each magnitude.

Keywords

• aerosol optical depth（aod）
• cma-meso three-dimensional variational analysis
• cuace
• himawari-8