Research On The Characteristics Of The Vertical Structure Of Precipitation In South China And South China Sea

The flood season in South China,as the first stage of the rainy season in China,has always been a hot issue in forecasting and research,but its understanding of the microscopic vertical characteristics of precipitation-cloud macros is not enough.In addition,the South China Sea,which is closely related to South China,is limited by its observations and its exploration of the vertical structure of precipitation.GPM(Global Precipitation Measurement)DPR(Dual-frequency Precipitation Radar)as a replacement for TRMM PR(Tropical Rainfall Measuring Mission Precipitation Radar),has accumulated a large amount of detection data since March 2014,and has become an effective means for exploring three-dimensional structure of precipitation.At present,the research on GPM DPR data mainly carries out the work of precipitation inversion algorithm evaluation and product evaluation through case study or short time series statistics.The previous research conclusions continuously optimize and confirm the GPM DPR data and its reliability.Based on the advantages of GPM DPR data for the optimization of 3D detection of strong and weak precipitation and the complement of the detection range on the tropical ocean surface,this paper reveals the macro-microscopic vertical structure climatic features of precipitation in South China(SC)and South China Sea(SCS),and discusses the difference of land and sea.(1)Characteristics of climatic of vertical structure in precipitation in South ChinaThe rapid growth of convective precipitation reflectivity mainly occurs in the lower layer,and the stratiform is located near the bright zone.The magnitude of the reflectivity increase of the two types of precipitation in the vertical direction is proportional to the rainfall intensity.When heavy precipitation occurs,the particle concentration of convective precipitation is not always higher than the stratiform,but the former has a larger particle radius than the latter;strong stratiform precipitation often comes from the aggregation of uniformly sized particles,which does not form larger droplets of diameter.Convective precipitation in winter accompanied by the increase of rain intensity,the contribution of precipitation in the coalescence layer is reduced first and then increased and the contribution of precipitation in ice-water mixed layer is the first increase and then decrease.Stratiform precipitation in summer accompanied by the increase of rain intensity,the contribution of precipitation in the uniform layer is increased,at the same time,the contribution of the ice-water mixed layer is reduced,and the winter contribution trend is consistent with the summer,but the specific gravity is relatively reduced.The high concentration and large-scale particles of convective precipitation in early rainy season are more conducive to higher development,while the vertical distribution of the concentration and radius of the stratiform particles is basically the same in early/latter rainy season in South China.Whether it is convective or stratiform,the concentration of low-level particles in strong precipitation is lower than that in latter rainy season in South China,but the radius of low-level precipitation particles in early rainy season is larger,indicating that the strong precipitation in the early rainy season is active in the lower layer.As for the formation of particles,the scale is larger.The peak-to-high similarities and differences between early and latter rainy seasons are mainly in the central part of Guangxi and the coastal areas of central Guangdong: the precipitation produced by the tropical disturbance in the western part of Guangxi in latter rainy season is stronger;There is a drop in the top of the storm in Guangdong near the Pearl River Delta in latter rainy season.This downward trend is particularly evident in convective precipitation.It can be seen that the development of monsoon precipitation and convective processes in the Pearl River Delta region during early rainy season is significantly stronger than that in latter rainy season.(2)Differences in vertical structure of precipitation in South China and South China SeaThe frequency of convective precipitation particle radius greater than 1.6mm in SCS is higher than that of SC.Large-scale particles of stratiform can be left at a frequency increase of more than 4 km,and at the same time,the height is lowered,and the high-frequency center is decreasing,which is inseparable from the huge evaporation on the ocean surface.The average profile of particle concentration and radius shows that strong convective precipitation in SCS tends to exist in a "high concentration,small scale" state.The seasonal variation of the storm top height in the land of SC is stronger than SCS.The shallow convective precipitation on the land is affected by the monsoon from the spring to the autumn,and the deep convection increases significantly in the summer.Although there is no obvious seasonal variation in the storm top height in the SCS,there are bimodal features.The two types of precipitation peaks appear at 3 km and 5.5 km,corresponding to cumulus clouds,rain clouds and high cumulonimbus clouds.