大气科学学报2018，Vol.41Issue(2)：155-166,12.DOI:10.13878/j.cnki.dqkxxb.20160202001
一次梅雨锋暴雨发生发展机制的诊断与模拟
Diagnosing analysis and numerical simulation of formation and development mechanism of a rainstorm associated with Meiyu front
摘要
Abstract
Using the NCEP/NCAR reanalysis data,FY2E satellite data and the automatic weather station data,combined with the WRF(Weather Research and Forecasting) model,a Meiyu rainstorm occurred in Jiangsu and Anhui provinces in 2013 was analyzed.Observational data analysis results show that under favorable circulation background and thermodynamic conditions,the heavy rain occurs in the south warm side of Meiyu front,with a common influence of Northeast cold vortex,Meiyu front and Changjiang-Huaihe shear line.The water vapor is mainly from the northwest of South China Sea.Convective instability and symmetric instability locate in the rainstorm zone,which is favorable for the common development of both vertical convection and ramp-up airflow.The rain belt transforms from the ribbon to string shape distributions and moves southward along with Meiyu front.Early precipitation is triggered by the surface mesoscale convergence line,directly affected by two successive meso-α-scale linear convective systems.Later rainfall is triggered by the ground warm shear line.There are a string of meso-β-scale convective systems developing eastward along the shear line.High-resolution model outputs analysis results reveal that the large scale non-geostrophic forcing also plays an important role in triggering strong convection during the rainstorm.The ground convergence line produces a banded lower layer convergence zone,resulting in strip continuous distribution of ascending motion,which gives rise to linear convection system and banded precipitation.Additionally,the ground convergence line can form two mesoscale vertical secondary circulations in the north and south of rainstorm area,which is the precipitation enhancement mechanism.The local disturbance of warm shear line produces local strong convergence at low altitude,thus making strong ascending and weak descending interval distribute along the shear line.And then those convective systems develop in the strong ascending regions,bringing local heavy precipitation.关键词
梅雨锋暴雨/中尺度对流系统/辐合线/暖式切变线/数值模拟Key words
Meiyu front rainstorm/mesoscale convective system/convergence line/warm shear line/numerical simulation引用本文复制引用
闵锦忠,张申龚,杨婷..一次梅雨锋暴雨发生发展机制的诊断与模拟[J].大气科学学报,2018,41(2):155-166,12.基金项目
国家重点基础研究发展计划(973计划)项目(2013CB430102) （973计划）
国家自然科学基金重点资助项目(41430427) （41430427）
江苏省高校自然科学重大基础研究项目(11KJA170001) （11KJA170001）
