气象学报2018，Vol.76Issue(3)：323-342,20.DOI:10.11676/qxxb2018.001
一次华南暖区暴雨过程可预报性的初值影响研究
A study of the impact of initial conditions on the predict-ability of awarm-sector torrential rain over South China
摘要
Abstract
The warm-sector torrential rain in South China often occurs in the warm sector 200－300 km ahead of a cold front or without a cold front.Because of the lack of distinct synoptic systems,the predictability of this type of rain is at a very low lev-el.To discuss the impact of initial moisture condition on warm-sector convection triggering and development,two numerical ex-periments (the control run CTRL and the cloud analysis run CLD)are designed to study a case occurred over the western coast of Guangdong province on 16 May 2015.These experiments are conducted using 3-km resolution mesoscale GRAPES (Global/Regional Assimilation and PrEdiction System)model and ADAS (ARPS Data Analysis System)complex cloud analysis system. Results show that:(1)the initial condition of cloud analysis run CLD is characterized by higher moisture content,more insta-ble stratification,larger convective available potential energy,increased K index and precipitable water,and lower lifting con-densation level and convective inhibition,and smaller LI index.Thereby the vertical velocity is enhanced and the convection is triggered more quickly;(2)there exist some differences between the mechanisms for the warm-sector convection triggering and development,i.e.,the triggering is enhanced by latent heat released from water vapor condensation,which contributes to the positive buoyancy;during the convection development period,convergence is caused by the outbreak of the surface cold pool and the warm advection from the sea.Sensitivity experiments further indicate that when reducing the water vapor content to 70%,the initial convergence is weakened,and the convection triggering is subsequently weakened,while the dissipation is also delayed.These results can increase our understanding of the predictability of warm-sector torrential rain in South China.Spe-cifically,results of the present study can be used as a reference for future development of operational cycling assimilation sys-tem.关键词
暖区暴雨/初值/对流触发/对流维持Key words
Warm-sector torrential rain/Initial conditions/Convection triggering/Convection maintenance分类
天文与地球科学引用本文复制引用
吴亚丽,蒙伟光,陈德辉,林文实,朱立娟..一次华南暖区暴雨过程可预报性的初值影响研究[J].气象学报,2018,76(3):323-342,20.基金项目
国家自然科学基金(41675099、41705035)、广东省科技计划项目(2017A020219005)、广州市科技计划项目(201604020012). （41675099、41705035）
