This paper discusses the effect of graupel/hail parameters on a convective system in Yangjiang, Guangdong Province. The simulation results using the original model settings were similar to observations in terms of rad...This paper discusses the effect of graupel/hail parameters on a convective system in Yangjiang, Guangdong Province. The simulation results using the original model settings were similar to observations in terms of radar reflectivity and sea level pressure, as well as the identification of hydrometeor particle classification by X-band dual-polarization radar data. Sensitivity tests using changed parameters of graupel/hail indicated that a size distribution with larger and denser but fewer hail hydrometers resulted in a weaker development of the convective system in the horizontal and vertical directions. With a large terminal velocity of hail, the melting rate of graupel and evaporation rate of rain were the lowest. Hail could reach the ground and the mixing ratio of rain was the largest near the ground. Precipitation, including rainwater and hail, was the largest. However, a size distribution with smaller and lighter but numerous graupel hydrometers resulted in a stronger development of the convective system. The melting rate of graupel and evaporation rate of rain were the largest. More graupel particles were stranded in the air for a longer time—and the maximum mixing ratio of rain was the largest. The precipitation amount, including rainwater only, was the smallest. The changes to graupel parameters also led to differences in microphysical processes.展开更多
The horizontal resolution of global numerical weather prediction models is continuously developing. However, due to the imperfect precipitation simulation/forecast of these models, the demand for considering riming pa...The horizontal resolution of global numerical weather prediction models is continuously developing. However, due to the imperfect precipitation simulation/forecast of these models, the demand for considering riming particles in cloud microphysical schemes in these models is increasing. This study employed the latest versions of global atmospheric reanalysis data (ERA5), the satellite retrieval data of the Global Precipitation Observation Program (GPM),and station precipitation observations to explore the impacts of adding graupel to the cloud microphysical scheme in the China Meteorological Administration-Global Forecast System (CMA-GFS) on summer regional precipitation simulations in four Chinese climate zones. The results verify that the new graupel scheme can enable CMA-GFS to decently predict global graupel distribution, especially in tropical and midlatitude regions. The addition of graupel in the cloud microphysics increases the precipitation simulation in North China, while that in Southwest China is weakened and dispersed. Moreover, graupel scheme increases the precipitation simulations of almost all magnitudes.The increase in light rain is obvious, and the absolute value of heavy rain is strengthened. This may be because graupel quickly melts into rain after falling out of the zero-temperature layer due to its large mass and fast falling speed, increasing surface precipitation. In summary, the addition of graupel in the cloud microphysical scheme can improve CMA-GFS’s underestimation of strong precipitation.展开更多
基金supported by the National Basic Research Program of China (973 Program, Grant Nos. 2014CB441403 and 2013CB430105)the National Natural Science Foundation of China (Grant No. 41205099)+1 种基金Guizhou Province Scientific Research Joint Project (Grant No. G[2013]4001)the Special Scientific Research Project of the Meteorological Public Welfare Profession of China (Grant No. GYHY201006031)
文摘This paper discusses the effect of graupel/hail parameters on a convective system in Yangjiang, Guangdong Province. The simulation results using the original model settings were similar to observations in terms of radar reflectivity and sea level pressure, as well as the identification of hydrometeor particle classification by X-band dual-polarization radar data. Sensitivity tests using changed parameters of graupel/hail indicated that a size distribution with larger and denser but fewer hail hydrometers resulted in a weaker development of the convective system in the horizontal and vertical directions. With a large terminal velocity of hail, the melting rate of graupel and evaporation rate of rain were the lowest. Hail could reach the ground and the mixing ratio of rain was the largest near the ground. Precipitation, including rainwater and hail, was the largest. However, a size distribution with smaller and lighter but numerous graupel hydrometers resulted in a stronger development of the convective system. The melting rate of graupel and evaporation rate of rain were the largest. More graupel particles were stranded in the air for a longer time—and the maximum mixing ratio of rain was the largest. The precipitation amount, including rainwater only, was the smallest. The changes to graupel parameters also led to differences in microphysical processes.
基金Supported by the National Key Research and Development Program of China (2021YFC3090205)National Natural Science Foundation of China (42090032)。
文摘The horizontal resolution of global numerical weather prediction models is continuously developing. However, due to the imperfect precipitation simulation/forecast of these models, the demand for considering riming particles in cloud microphysical schemes in these models is increasing. This study employed the latest versions of global atmospheric reanalysis data (ERA5), the satellite retrieval data of the Global Precipitation Observation Program (GPM),and station precipitation observations to explore the impacts of adding graupel to the cloud microphysical scheme in the China Meteorological Administration-Global Forecast System (CMA-GFS) on summer regional precipitation simulations in four Chinese climate zones. The results verify that the new graupel scheme can enable CMA-GFS to decently predict global graupel distribution, especially in tropical and midlatitude regions. The addition of graupel in the cloud microphysics increases the precipitation simulation in North China, while that in Southwest China is weakened and dispersed. Moreover, graupel scheme increases the precipitation simulations of almost all magnitudes.The increase in light rain is obvious, and the absolute value of heavy rain is strengthened. This may be because graupel quickly melts into rain after falling out of the zero-temperature layer due to its large mass and fast falling speed, increasing surface precipitation. In summary, the addition of graupel in the cloud microphysical scheme can improve CMA-GFS’s underestimation of strong precipitation.
