Comparative Analysis Of Atmospheric Aerosol Radiative Parameterization Schemes

Focused on the improvement of the aerosol radiative forcing parameterization in atmospheric numerical model, the paper discussed the influence of urban aerosol radiative effect on atmospheric boundary layer (ABL) over Lanzhou based on some previous researches, and performed some corresponding numerical simulations using the WRFABL model system, which was made up of nested model WRFv2.1 and a comprehensive ABL model in which the aerosol radiation effect and diffusion were considered. Then through the comparison of arithmetic of different radiative transfer equation, a further exploration of the aerosol radiative effect simulation was made.First of all, using NNRP2 data from NCEP/NCAR and the outfield observation data of Lanzhou (the meteorological data and air quality data of ABL measurement campaign during December 1989 in Lanzhou), the verification of the model system was worked out for WRF model and the ABL model, which showed that the two models could run steadily and the performance of the meteorological simulation was preferable. Secondly, based on the framework of DISORT, a radiative transfer scheme was developed which was suitable for the aerosol optical characteristics over Lanzhou, and then a comparison with the other radiative transfer scheme based on LOWTRAN 7 was made. It showed that their calculated results of the shortwave heating rates and long wave cooling rates in the polluted ABL were approximately similar. Finally, the influences of the two radiative transfer schemes on the meteorological field simulations by WRFABL model were analyzed. The results showed that, for the aerosol radiative effect of smoke layer in Lanzhou in clear sky, their influences were similar, with which the aerosol radiative effect could be well reflected in the WRFABL model, i. e. the simulations of the wind and temperature fields were more reasonable compared with the observations.This work could be of benefit to the further study of the simulation of the urban aerosol direct radiative forcing.