琼州海峡两次高压后部型海雾的对比分析和数值模拟  

Comparison and Numeric Simulation of Two Sea Fog Processesbehind High Pattern over Qiongzhou Strait

作　　者：杨薇[1,2] 张春花[1,2] 冯箫[1,2] 李勋 林建兴 YANG Wei;ZHANG Chunhua;FENG Xiao;LI Xun;LIN Jianxing(Hainan Meteorological Services,Haikou 570203,Hainan,China;Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province,Haikou 570203,Hainan,China)

机构地区：[1]海南省气象台,海南海口570203 [2]海南省南海气象防灾减灾重点实验室,海南海口570203

出　　处：《高原气象》2022年第3期762-774,共13页Plateau Meteorology

基　　金：中国气象局预报员专项项目(CMAYBY2020-101);海南省气象局技术提升项目(HNQXJS201801)。

摘　　要：利用中尺度数值模式WRF和NCEP分析资料,对2018年2月17-20日和2019年2月4-6日春节期间发生在琼州海峡的两次持续性海雾过程进行数值模拟,结合中国气象局陆面数据同化系统的能见度格点数据、卫星、自动站等观测资料,对两次海雾天气的天气背景、发展演变过程、水汽条件、动力条件和云—雾辐射作用进行比较研究。结果表明:两次海雾过程均发生在入海变性冷高压后部,2018年海雾过程为偏东方向的水汽输送,低层湿层深厚,不断增长的湿度和强烈的水汽辐合使得平流雾持续时间超过10 h,最低能见度达100 m。同时海雾发展期间伴随云雾共存现象,中层云区的存在白天可减小地面接收的短波辐射,减弱增温效应,夜间起到保温作用,近地面较低的温度和逆温层稳定维持,对海雾的长时间发展和维持起到促进作用;2019年海雾过程东南方向的水汽输送偏弱,湿层浅薄,海雾由陆地发展延伸而来,发展面积小,日出后很快消散。Using mesoscale numerical forecasting model WRF and National Centers for Environmental Prediction(NCEP)reanalysis data,two persistent sea fog events on 17-20 February 2018 and 4-6 February 2019 over Qiongzhou strait were simulated.Combined with visibility data of CMA Land Data Assimilation System,satellite and ground observations,the weather background,maintenance and development,water vapor transport,dynamic condition and cloud-fog structure of two sea fog processes were compared and analyzed.The results indicated that both persistent sea fog cases occurred at the back of denatured cold high moving in to the sea.During the 2018 sea fog events period,easterly water vapor convergence was strong,the high relative humidity in the lower layer was deep.The increasing relative humidity and strong water vapor convergence caused the advection fog last for more than 10 hours,with a minimum visibility of 100 m.Meanwhile,the mid-level cloud coexist with sea fog could reduce the shortwave radiation received by the ground in the daytime and weaken the warming effect,while played a role in heat preservation at night making surface-based lower temperature and inversion layer stability maintenance.Thus,the presence of clouds above the fog had a great effects on the maintenance and development of the lasting fog event.During the 2019 sea fog events period,the southeast water vapor convergence was weak,the high relative humidity was shallow,the sea fog with small area in Qiongzhou Strait developed first from inland,and dissipated after sunset.

关 键 词：琼州海峡 海雾 WRF模式 数值模拟 云雾共存 

分 类 号：P447[天文地球—大气科学及气象学]