Adaptability Of Cloud Microphysical Parameterization Scheme To Tropical Cyclone Simulation In The WRF/HWRF Model

Cloud microphysical processes and their feedback effects on the atmosphere are the main reasons for the uncertainty of the model forecast.The reasonable description of cloud microphysical processes is an important factor to improve the accuracy of tropical cyclone prediction.Therefore,Lin,WSM 6,Thompson and WDM 6 schemes in the WRF model and WSM 6 and Thompson scheme in the HWRF model are selected,combined with CloudSat satellite data,FY satellite data,MODIS data,EC reanalysis data,NCEP reanalysis data and CMA typhoon best track data to evaluate the adaptability ofdifferent parameterization in tropical cyclones' simulation,the conclusions are as follows :(1)The simulation results of different cloud microphysical schemes have little difference in the large-scale circulation situation,but there are great differences in the simulation results of cloud hydrides.In the WRF model,the cloud ice content simulated by Thompson scheme is higher than that of other parameterized schemes,and the spatial distribution of cloud ice simulated by Thompson scheme is the closest to observation.In the HWRF model,the cloud ice simulated by Thompson scheme is higher than that by WSM 6 scheme,and the distribution range of cloud ice is different from observation.(2)In the WRF model,Thompson scheme has the most ice particles,and Lin scheme has the least.The simulation results of WSM 6 and WDM 6 are very close.Above the 5km melting layer,the intensity and height of radar reflectivity strong echo area simulated by the four schemes are greater than CloudSat observation.In the HWRF model,the cloud ice content simulated by Thompson scheme in the HWRF model is higher than that in WSM 6 scheme,and the cloud ice content simulated by WSM 6 scheme is less than that by observation,and the distribution range of cloud ice is different from observation.The distribution height of cloud ice simulated by tropical low pressure is higher than that of observation,but it is lower than that of observation during strong typhoon.(3)In the WRF model,the distribution height and content of cloud ice and snow particles simulated by Lin scheme are higher than those of other schemes,and most of the snow particles are formed by the collision process of cloud ice particles.The cloud ice content simulated by Thompson scheme is significantly less than that of other parameterized schemes,which indicates that cloud ice particles in Thompson scheme will convert to snow particles rapidly.However,the vertical velocity of WSM6 is significantly higher than that of WDM 6,and more snow particles and graupel particles melt into rain water in the warm layer under the action of downdraft.The results show that the distribution of cloud ice is the highest,followed by snow particles and graupel particles.All the ice particles are basically distributed above the0? layer,while the rain water is distributed below the 0? layer.The results show that graupel particles are distributed in the area with high vertical velocity,and the growth of flocs is active;rainwater is mainly generated by the melting and transformation of graupel particles brought by downdraft in the lower layer.In Thompson scheme,the conversion rate of cloud ice particles to snow particles is very high.The vertical velocity of WSM 6 scheme is higher than that of Thompson scheme,and the conversion between graupel particles and rainwater is more.The precipitation rate detected by CloudSat is lower than that simulated by HWRF model,and the area with higher precipitation rate is consistent with the distribution area of rainwater.(4)The results show that the HWRF has a good simulation effect on typhoon track,the minimum pressure fluctuation of HWRF simulation cyclone center is larger,the simulation effect is better when the typhoon intensity is weak,and the simulation effect of HWRF simulation cyclone is weak during the strong cyclone observation intensity.The maximum wind speed at the center and the minimum sea level pressure have the same rule.(5)The temperature in stratosphere of typhoon simulated by HWRF changes violently,and the warm zone extends from high altitude to ocean surface.The higher temperature of ocean provides energy for typhoon development,and the rise of warm and humid air supports the development of typhoon warm center.After the typhoon moved close to the land,the warm center structure was greatly affected by the southwest warm and humid air flow.The central temperature anomaly shows that the warm center height of the simulated typhoon decreases first and then increases rapidly and maintains at a certain height.Moreover,with the development of typhoon intensity,the warm center intensity of typhoon also increases.The warm center of HWRF simulation is consistent with the typhoon center and is located in the upper air.The range of warm center decreases with the decrease of height,which is consistent with the funnel-shaped spatial structure of tropical cyclones.Moreover,the reanalysis data of ERA 5 also prove the funnel structure of ‘Lekima'.