Evaluation and Analysis of Simulation Capability of Hydrometeor Variables in Numerical Models Based on TMI Products

Based on the measured and retrieved products of the TMI (TRMM Microwave Imager) on board TRMM (Tropical Rainfall Measuring Mission) and combined with the microwave radiative transfer model, the simulation capability of hydrometeor variables of typhoon Chaba (0417) in the AREM (Advanced Regional Eta-coordinate Model) and the WRF (Weather Research and Forecasting) model is verified. First, the simulated track and rain of typhoon are studied and they are consistent with the best track and retrieved rain from the TMI, respectively. Then the simulated hydrometeor variables with the AREM and the WRF model are used as the input data of the microwave radiative transfer model to calculate microwave TBs (brightness temperatures). By comparing the simulated and measured TBs, the hydrometeor structures from the AREM and the WRF model are verified indirectly. Moreover, the hydrometeor structures are verified with the retrieved data from the TMI directly. The results show that, the content of cloud liquid water is overestimated by the AREM while the content of precipitation ice is underestimated. The WRF model underestimates the area of liquid hydrometeors, but the WRF model has better performance than AREM in the forecasting of frozen hydrometeors. Both the models perform well in the simulation of water vapor.