春季东海黑潮锋影响强对流的个例分析  

Case study of the East China Sea Kuroshio front effect on strong convection in spring

作　　者：周解梦 张苏平 张银意[3] ZHOU Jiemeng;ZHANG Suping;ZHANG Yinyi(College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;Key Laboratory of Physical Oceanography (Ocean University of China), Ministry of Education, Qingdao 266100, China;Lianyungang Meteorological Bureau, Lianyungang 222006, China)

机构地区：[1]中国海洋大学海洋与大气学院,山东青岛266100 [2]中国海洋大学物理海洋教育部重点实验室,山东青岛266100 [3]连云港市气象局,江苏连云港222006

出　　处：《海洋气象学报》2022年第2期11-21,共11页Journal of Marine Meteorology

基　　金：国家自然科学基金项目(41876130,41975024);国家重点研发计划项目(2019YFC1510102)。

摘　　要：利用卫星观测和再分析资料,研究了2018年4月30日东海黑潮海面温度锋(黑潮锋)影响低云突破边界层发展为对流云团,并导致强降水的过程。结果表明:(1)29日12时东海500 hPa上受短波槽控制,低空处于高低压之间的偏南气流中;黑潮锋大气边界层稳定,有利于低云发展。(2)黑潮锋的暖水侧向大气不断输送热量和水汽,稳定性减弱;而冷水侧对大气的冷却作用显著,大气稳定性增加。(3)经过约12 h的调整,黑潮锋通过垂直混合机制强迫表层风速发生变化,在黑潮锋上空形成风速辐合,叠加背景辐合场,导致辐合明显增强。(4)受平流效应影响,黑潮锋上空大气增湿增温,抬升凝结高度降低。(5)潜热释放与低空辐合之间形成正反馈,最终导致对流云团发展,降水强度显著增强。Using satellite observations and reanalysis data,this paper reveals a process that a sea surface temperature front associated with the East China Sea Kuroshio(the Kuroshio front)induces low clouds within the atmospheric boundary layer(ABL)to evolve into convective clouds,which leads to heavy precipitation on 30 April 2018.The results are shown below.(1)At 12:00 UTC 29 April,500 hPa is controlled by a short-wave trough,while low altitude is dominated by southerly air flow between high and low pressure in the East China Sea.ABL above the Kuroshio front is stable,inducing the development of low clouds.(2)The warm flank of the Kuroshio front acts to destabilize ABL through delivering heat and moisture to the air,while the cold flank has a significant cooling effect on the air,strengthening the stability of ABL.(3)After about 12 hours,modifications of surface wind speeds are induced by the Kuroshio front through vertical mixing mechanism,resulting in the formation of wind speed convergence over the Kuroshio front.Superimposed with the background field,it generates a prominent enhancement of the convergence.(4)Moreover,the air over the Kuroshio front gets warmer and moister by advection,lowering the lifting condensation level.(5)The positive feedback between latent heat release and surface wind convergence promotes the growth of deep convective clouds with significantly enhanced precipitation intensity eventually.

关 键 词：东海黑潮锋 大气边界层 表层风辐合 潜热释放 

分 类 号：P731.2[天文地球—海洋科学] P458.3