Using a double-parameter non-hydrostatic elastic three-dimensional model with detailed microphysical processes, the authors simulate the heavy rainfall event in South China which occurred on 9 June 1998 and lasted Tor...Using a double-parameter non-hydrostatic elastic three-dimensional model with detailed microphysical processes, the authors simulate the heavy rainfall event in South China which occurred on 9 June 1998 and lasted Tor more than 3 hours. This case is a supercell, and the upward and downward drafts interact with each other, which transfers rich water vapor at the converging position to upper levels, and the two drafts together maintain the convective course. The vertical heating profiles and contributions to water matter of five kinds of micro-phase processes are revealed quantitatively in the results. Condensation releases the most heat, which is more than that of the absorption by evaporation and melting. The rain particles first come from the autoconversion of cloud particles, the warm-rain process; later from the cold-rain process, the melting of grauple particles. The precipitation intensity reaches 75 mm h?1 while its efficiency remains high. The total amount of rain is 32 mm, a value close to the observations of nearby stations.展开更多
Using the numerical model of mixed convective-stratiform clouds(MCS)in the paper(Hong 1997)and the averaged stratification of torrential rain processes,the evolution processes, interaction of the two kinds of clouds,s...Using the numerical model of mixed convective-stratiform clouds(MCS)in the paper(Hong 1997)and the averaged stratification of torrential rain processes,the evolution processes, interaction of the two kinds of clouds,structure and the precipitation features in the MCS to produce heavy rain are simulated and studied,and the physical reasons of producing torrential rain are analysed.The results indicate that the stratiform cloud surrounding the convective cloud becomes weakened and dissipates in the developing and enhancing of the convective cloud,and the rainfall rate and water content in the stratiform cloud increase as the distance from the convective cloud becomes larger.The numerical experiments find out that the stratiform cloud provides a benificial developing environment for the convective cloud,i.e.,the saturated environment and the convergence field in the stratiform cloud help to lengthen the life cycle of the convective cloud, produce sustained rainfall with high intensity and intermittent precipitation with ultra-high intensity.These and the ice phase microphysical processes are the main factors for the torrential rain formation and the MCS is a very effective precipitation system.展开更多
基金This work was supported jointly by National Key Basic Research Project G1998040912,95 Special Topic of Key National Project:"Torrential Rainfall Experiment over the Both Side of the Taiwan Strait and Adjacent Area"(95-special-03) and the National
文摘Using a double-parameter non-hydrostatic elastic three-dimensional model with detailed microphysical processes, the authors simulate the heavy rainfall event in South China which occurred on 9 June 1998 and lasted Tor more than 3 hours. This case is a supercell, and the upward and downward drafts interact with each other, which transfers rich water vapor at the converging position to upper levels, and the two drafts together maintain the convective course. The vertical heating profiles and contributions to water matter of five kinds of micro-phase processes are revealed quantitatively in the results. Condensation releases the most heat, which is more than that of the absorption by evaporation and melting. The rain particles first come from the autoconversion of cloud particles, the warm-rain process; later from the cold-rain process, the melting of grauple particles. The precipitation intensity reaches 75 mm h?1 while its efficiency remains high. The total amount of rain is 32 mm, a value close to the observations of nearby stations.
文摘Using the numerical model of mixed convective-stratiform clouds(MCS)in the paper(Hong 1997)and the averaged stratification of torrential rain processes,the evolution processes, interaction of the two kinds of clouds,structure and the precipitation features in the MCS to produce heavy rain are simulated and studied,and the physical reasons of producing torrential rain are analysed.The results indicate that the stratiform cloud surrounding the convective cloud becomes weakened and dissipates in the developing and enhancing of the convective cloud,and the rainfall rate and water content in the stratiform cloud increase as the distance from the convective cloud becomes larger.The numerical experiments find out that the stratiform cloud provides a benificial developing environment for the convective cloud,i.e.,the saturated environment and the convergence field in the stratiform cloud help to lengthen the life cycle of the convective cloud, produce sustained rainfall with high intensity and intermittent precipitation with ultra-high intensity.These and the ice phase microphysical processes are the main factors for the torrential rain formation and the MCS is a very effective precipitation system.
