海南岛秋汛期特大暴雨局地锋生的特征及其对对流系统发展的影响  

Characteristics of local frontogenesis and its impact on the development of convective system during the autumn flood season over Hainan Island

作　　者：冯文[1] 吴冰雪 杨薇[1] FENG Wen;WU Bingxue;YANG Wei(Hainan Meteorological Observatory,Haikou 570311,China;School of Atmospheric Sciences,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]海南省气象台,海南海口570311 [2]南京信息工程大学大气科学学院,江苏南京210044

出　　处：《大气科学学报》2023年第2期271-282,共12页Transactions of Atmospheric Sciences

基　　金：海南省自然科学基金高层次人才项目(422RC803)。

摘　　要：基于WRF模式的模拟结果,结合地面观测资料、雷达回波资料以及ECMWF ERA5再分析资料,对2010年10月1—8日发生在海南岛的一次持续性秋汛期特大暴雨过程中局地锋生与对流发展的相互作用机制进行了深入分析,发现:在海南岛秋汛期特大暴雨的锋生过程中,环境场起到主要作用。非绝热加热项F_(1)和水平运动项F_(3)在局地锋生的过程中贡献最大,且两者的正极大值区在强降水地区多时次重叠出现,表明非绝热加热和水平形变辐散是导致强降水区强烈锋生的主要原因。此外,模拟结果和实况观测对比分析发现,较低的凝结高度导致最强降水时段对流低层出现强潜热释放,对流区低层气团内部增暖,形成强烈锋生效应,低层强的锋生导致上升气流加速,深对流发展加强,暴雨增幅。与垂直运动有关的倾斜项F_(2)相比,非绝热加热项F_(1)和水平运动项F_(3)贡献虽小,但在夜间有增大的现象,分析表明夜间暴雨区垂直速度ω水平分布的差异性对深对流的加强有重要作用。Based on the WRF-simulated results,surface observation data,radar data,and the ECMWF ERA-5 reanalysis data,this paper analyzes the characteristics of local frontogenesis and its influence on the development of convective systems during the heavy rainstorm occurred on October 1—8,2010,in Hainan Island.The results show that the environmental field played a major role in the frontogenesis process of this heavy rain event.The non-adiabatic heating term and the horizontal motion term contribute the most to the process of local frontogenesis,and the largest positive value area of the two overlaps many times in the heavy precipitation area,indicating that diabatic heating and horizontal deformation divergence are responsible for the strong frontogenesis in this area.In addition,the comparison and analysis of simulated results and observations show that the lower condensation height leads to strong latent heat release in the lower convective layer during the period of the strongest precipitation,and that the internal warming of the lower air mass in the convective zone creates a strong frontogenesis effect.The strong frontogenesis at the lower level accelerates the updraft,strengthens the development of deep convection,and intensifies the torrential rain.Compared with the diabatic heating term and the horizontal movement term,the contribution of the vertical motion tilting term related to vertical movement is small,but it increases at night.The analysis shows that the difference in the horizontal distribution of vertical velocity at night plays an important role in the enhancement of deep convection in areas with heavy rainfall.

关 键 词：海南岛 特大暴雨 锋生函数 对流发展 模拟分析 

分 类 号：P458.121.1[天文地球—大气科学及气象学]