摘要
By using NCEP reanalysis data,the formation reason of a disaster weather process which happened in Fujian Province on April 1,2007 was analyzed. The results showed that this strong convection weather process was caused by the development of convective thunderstorm monomer in the warm zone of jet stream which was in front of ground front at afternoon. The invasion of cold advection in the middle-high layer had the major trigger effects on this strong convection weather occurrence. The tilt development of vorticity was easy to appear in θse tilted frontal zone,which made a large amount of latent heat release exist in the middle layer of troposphere. Meanwhile,it favored the potential vorticity in the middle layer to download. Thus,it made the important contributions to the development,maintenance of low-altitude vorticity in the strong convection zone and favored the development,maintenance of thunderstorm. In the middle-low layer of troposphere where the strong convection happened,the distribution of meso-scale wave train which was similar to the gravity wave appeared. Meanwhile,it also reflected the wave characteristics which the ascending motion alternated with the descending motion in the divergence. The westerly disturbance in the middle-low layer of troposphere,the southerly disturbance in the low altitude and the middle-upper layer of troposphere made the important contributions to the strong convection weather. The easterlies disturbance and the divergence effect in the tropopause strengthened the development of vertical motion. The strong vertical wind shear was the favorable condition of strong convection weather occurrence.
By using NCEP reanalysis data,the formation reason of a disaster weather process which happened in Fujian Province on April 1,2007 was analyzed. The results showed that this strong convection weather process was caused by the development of convective thunderstorm monomer in the warm zone of jet stream which was in front of ground front at afternoon. The invasion of cold advection in the middle-high layer had the major trigger effects on this strong convection weather occurrence. The tilt development of vorticity was easy to appear in θse tilted frontal zone,which made a large amount of latent heat release exist in the middle layer of troposphere. Meanwhile,it favored the potential vorticity in the middle layer to download. Thus,it made the important contributions to the development,maintenance of low-altitude vorticity in the strong convection zone and favored the development,maintenance of thunderstorm. In the middle-low layer of troposphere where the strong convection happened,the distribution of meso-scale wave train which was similar to the gravity wave appeared. Meanwhile,it also reflected the wave characteristics which the ascending motion alternated with the descending motion in the divergence. The westerly disturbance in the middle-low layer of troposphere,the southerly disturbance in the low altitude and the middle-upper layer of troposphere made the important contributions to the strong convection weather. The easterlies disturbance and the divergence effect in the tropopause strengthened the development of vertical motion. The strong vertical wind shear was the favorable condition of strong convection weather occurrence.
基金
Supported by Fujian Natural Science Fund Plan Project(W0650004)
The Science and Technology Plan Project of Xiamen Technology Bureau(3502Z20064022)
