A mesoscale inertia-gravitational wave at 200 hPa is analysed. The reasons of this wave occurring are also discussed. It is indicated that the occurrence of this wave is due to inertia-gravitational instability, and c...A mesoscale inertia-gravitational wave at 200 hPa is analysed. The reasons of this wave occurring are also discussed. It is indicated that the occurrence of this wave is due to inertia-gravitational instability, and closely related to horizontal and vertical shear of wind.展开更多
Nowadays, the nested grid model is widely used to increase the resolution of numerical model. An attempt to investigate the influence of the newly developed nesting technique of WRF model on the mesoscale numerical si...Nowadays, the nested grid model is widely used to increase the resolution of numerical model. An attempt to investigate the influence of the newly developed nesting technique of WRF model on the mesoscale numerical simulation of severe storm is described in this article. The results of sensitivity tests infer that the WRF model give more accurate and vivid prediction of severe storm with nesting scheme. As is shown in the tests, simulating value of the precipitation centers using nesting scheme are larger than those without using nesting scheme, which indicates that the simulating precipitation of nested storm is closer to the real rainfall. And there is obvious improvement of distribution of rain area and position of precipitation centers. According to the high resolution output data of the WRF model, deep and detailed analysis of characters of the mesoscale system that triggers the rainstorm is reported in this article, and the thermal and dynamical characters of this Meiyu front severe storm are also discussed.展开更多
A mesoscale torrential rainfall event that occurred over eastern China in June 2013 is analyzed by using observational data.The results show that a mesoscale convergence line and a weak convective cloud line formed ov...A mesoscale torrential rainfall event that occurred over eastern China in June 2013 is analyzed by using observational data.The results show that a mesoscale convergence line and a weak convective cloud line formed over the northern part of the Hangzhou Bay during the onset of the torrential rainfall event.A meso-vortex appeared over the confluence point of northeasterly flow associated with the Yellow-Sea high,easterly flow from rainfall area,and southeasterly flow from the Hangzhou Bay.The meso-vortex with a horizontal scale of 10-20 km lasted for about 1 h for stable surface circulations.The analysis of radar retrieval reveals that the meso-vortex in the boundary layer occurred at the south of strong radar echo.The formation of the meso-vortex turned to enhance convergence and cyclonic vorticity in the lower troposphere,which strengthened updrafts that are tilted into convective clouds and caused torrential rainfall.Thus,the occurrence of the meso-vortex in boundary layer is one of the mechanisms that are responsible for the enhancement of convective development.展开更多
基金Project supported by the National Science Foundation of China
文摘A mesoscale inertia-gravitational wave at 200 hPa is analysed. The reasons of this wave occurring are also discussed. It is indicated that the occurrence of this wave is due to inertia-gravitational instability, and closely related to horizontal and vertical shear of wind.
基金Project supported by the National Natural Science Foundation of China (Grant No: 90411006)
文摘Nowadays, the nested grid model is widely used to increase the resolution of numerical model. An attempt to investigate the influence of the newly developed nesting technique of WRF model on the mesoscale numerical simulation of severe storm is described in this article. The results of sensitivity tests infer that the WRF model give more accurate and vivid prediction of severe storm with nesting scheme. As is shown in the tests, simulating value of the precipitation centers using nesting scheme are larger than those without using nesting scheme, which indicates that the simulating precipitation of nested storm is closer to the real rainfall. And there is obvious improvement of distribution of rain area and position of precipitation centers. According to the high resolution output data of the WRF model, deep and detailed analysis of characters of the mesoscale system that triggers the rainstorm is reported in this article, and the thermal and dynamical characters of this Meiyu front severe storm are also discussed.
基金Supported by the National Natural Science Foundation of China(41175047 and 41475039)National(Key)Basic Research and Development(973)Program of China(2013CB430104 and 2015CB953601)
文摘A mesoscale torrential rainfall event that occurred over eastern China in June 2013 is analyzed by using observational data.The results show that a mesoscale convergence line and a weak convective cloud line formed over the northern part of the Hangzhou Bay during the onset of the torrential rainfall event.A meso-vortex appeared over the confluence point of northeasterly flow associated with the Yellow-Sea high,easterly flow from rainfall area,and southeasterly flow from the Hangzhou Bay.The meso-vortex with a horizontal scale of 10-20 km lasted for about 1 h for stable surface circulations.The analysis of radar retrieval reveals that the meso-vortex in the boundary layer occurred at the south of strong radar echo.The formation of the meso-vortex turned to enhance convergence and cyclonic vorticity in the lower troposphere,which strengthened updrafts that are tilted into convective clouds and caused torrential rainfall.Thus,the occurrence of the meso-vortex in boundary layer is one of the mechanisms that are responsible for the enhancement of convective development.
