2021年“4·30”南通地区大风数值模拟与形成机理分析  

The formation mechanism and numerical simulation of the“4.30”gale in Nantong in 2021

作　　者：张月 葛旭阳[1] ZHANG Yue;GE Xuyang(Key Laboratory of Meteorological Disaster,Ministry of Education/Joint International Research Laboratory of Climate and Environment Change,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室,南京210044

出　　处：《气象科学》2025年第1期82-94,共13页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(42175003)。

摘　　要：2021年4月30日江苏省南通地区出现伴随飑线过程的冰雹、大风等强对流天气。本文利用WRF-ARW模式进行敏感性数值试验,以此探究环境背景场对对流系统生消演变过程的可能影响途径。结果表明,该大风天气与飑线系统的结构、强度密切相关。飑线冷池强度会影响大风的生成和强度,相应的动力和热力共同作用影响下沉气流的强度,进而影响地面风速。增加中层水汽会减弱冷池强度和范围,飑线强度减弱,移速变慢;关闭降水蒸发作用,产生的对流系统没有冷池,结构与飑线不同。冷池的减弱或消失使得下沉气流和低层辐散减弱,中层动量无法下传,进而导致地面风速减弱。A severe convective weather with hail and strong winds accompanied by the squall line process occurred in Nantong,Jiangsu Province on 30 April 2021.The WRF-ARW model was used to conduct sensitivity numerical experiments to investigate how the environmental field influences the evolution of the convective system.Results indicate that the strong winds weather was closely related to the structure and intensity of the squall line system.The intensity of the cold pool in the squall line affected the formation and intensity of the strong winds.The corresponding dynamic and thermal forces combined affect the intensity of the downdraft,thus affecting the surface wind speed.The intensity and range of the cold pool were weakened by the increase of middle-level water vapor,the squall line intensity was weakened and the moving speed was slow.When the raindrop evaporation was turned off,the resulting convective system had no cold pool,and its structure was different from the squall line.The weakening or disappearance of the cold pool weakens the downdraft,weakens the divergence in the lower layer,and the momentum in the middle layer cannot be transmitted downward,leading to the weakening of the surface wind speed.

关 键 词：飑线 数值模拟 冷池 地面大风 动量下传 

分 类 号：P458.123[天文地球—大气科学及气象学]