Characteristics And Mechanism Of Precipitation Over Fujian Province During Typhoon “sou Lik”(1307)

In this paper,the individual case of no.7 typhoon"soulik"in 2013 was analyzed,the circulation situation,automatic station data,radar echo and satellite cloud map of the typhoon process were comprehensively analyzed,and the physical change of heavy precipitation caused by the typhoon was diagnosed and analyzed.In order to understand the formation of the moving path of typhoon"soulik"and its physical mechanism such as rainstorm,the numerical simulation was carried out by means of the fully compressible and non-static mesoscale numerical forecast model WRF3.5,which was selected at 08pm to 8pm?integral time of 84 hours?on the 12th and 14th before and after the typhoon landed.High altitude and ground conventional data and satellite cloud images and radar echo data collection,"dispute resolution"landed in southern fujian southeast coast in fujian weather background and heavy rain to the torrential rain process system show that position of subtropical high by south can lead to the development of typhoon north of convection is restrained,formed a significant dynamic asymmetric structure stronger in the south than the north.The low-altitude jet stream and the ultra-low-altitude jet stream of 925 hPa were one of the reasons for the large-scale typhoon and rainstorm in southern fujian.The analysis of the vertical velocity,divergence,vorticity,water vapor flux and other changes of the physical quantity of heavy precipitation in the process of"soulik"shows that the fall area of typhoon rainstorm corresponds to the vertical upward movement area.The₀)-plane tilts,the vertical shear of zonal wind and the increase of wet-baroclinic property lead to the development of vertical vorticity,which is conducive to the maintenance of cyclones and the generation of heavy precipitation.The simulation results of the mesoscale numerical forecast model WRF3.5 on the process before and after typhoon"soulik"landed in fujian show that the WRF model can well simulate the development of typhoon"soulik"and reproduce the typhoon path and landing process strength and structure.The asymmetrical distribution of the strength of the south strong and the north weak is a favorable dynamic condition for the typhoon rainstorm.Vertical wind shear of high and low air environment has a direct impact on the asymmetric distribution of typhoon structure and precipitation structure.The lower layer presents the zone of warm and wet instability,the middle neutral layer and the stable situation of the upper layer are conducive to the deep convection movement and trigger the rainstorm.The position of sah and subtropical high relative to the typhoon may affect the distribution of wind field and divergence field around the typhoon,as well as the distribution of typhoon convergence area along with height change and low-altitude jet flow,thus having an important impact on the typhoon heavy precipitation area.