Multiple Aerosol Data Assimilation Based On MIE Observation Operator

In this paper,based on the WRF-Chem air pollution model,using the MOSAIC (Model for Simulating Aerosol Interactions and Chemistry)aerosol scheme,an assimilation based on the MIE scattering(scattering that occurs when the diameter of particles in the atmosphere corresponds to the wavelength of radiation)observation operator is constructed,which can assimilate the extinction coefficient achieved by lidar,atmospheric visibility,and aerosol mass concentration.In the assimilation experiment,data from March 2019 was used to calculate the background error covariance of 16 aerosol variables of the MOSAIC scheme using the NMC method.The results show that the distribution characteristics of the standard deviation of background error are different between different species,and the value changes with height,with the highest decline rate in the upper layer of the boundary layer.The background error level correlation coefficients of various species in the scheme are also different.The incremental field of the observation data during the assimilation for the background field improvement will produce different correction values in the horizontal direction.Assimilation using the observation information of ground pollution mass concentration in Beijing-Tianjin-Hebei area at 00:00 on March 1,2019,the aerosol extinction coefficient data observed by six Lidars including Haidian and Xiayunling areas,and the atmospheric visibility data measured by automatic observation stations nationwide data.The results show that the assimilation radar observation has a positive effect on the improvement of the background field,and the improvement effect is mainly reflected in the area where the observation information is concentrated.At the same time,the assimilation radar and ground PM data have a better effect,and the duration of the assimilation positive effect can reach 13 hours;The batch test results at 4times a day on the 1st to 5th of the month show that the assimilation radar data can basically improve the simulation of PM mass concentration,and the positive effect duration is 6-12 hours.Compared with the control test,the initial field RMSE of atmospheric visibility data assimilation test,ground pollution mass concentration concentration data assimilation test and two data simultaneous assimilation tests is reduced by 14.4(14.13%),62.3(61.11%),61.4(60.25%)The assimilation visibility data also has a positive effect on the simulation forecast,with a duration of more than16 hours.