摘要
2018年春节期间,琼州海峡持续6 d(2月15—20日)有雾,最低能见度不足200 m。主要从气象卫星监测上分析此次琼州海峡持续性海雾的时间演变特征,并从大气海洋条件分析形成持续性海雾的原因,得出如下结论:1)2018年2月华南东侧西太平洋海面温度较常年同期偏高,有3个暖海面温度距平中心,为持续性大雾提供暖湿气流;2)此次持续性大雾过程琼州海峡位于均压场,但西南低涡起着辅助的作用,致使海洋性的南风在边界层抵御了干燥的大陆性气团,利于维持边界层的湿度;3)低层流场为暖湿气流,925 hPa近地面湿层上空有一个干中心维持,“上干下湿”的湿度层结有利于海雾维持和向上发展形成一定厚度的海雾;4)低云增加和弱降水是使18日全天海雾得以维持的重要因素。
During the Spring Festival of 2018,there was a sustained fog process lasting for 6 days(from 15 to 20 February)over Qiongzhou Strait,during which the minimum visibility was less than 200 m.This paper mainly analyzes the temporal evolution of the sustained sea fog process over Qiongzhou Strait by satellite monitoring and reveals the reasons for its persistence based on atmosphere and ocean conditions.Firstly,the SST in western Pacific on the east of South China is higher than that in normal years with three higher sea surface temperature anomaly(SSTA)centers in February 2018,which provides warm and moist air for the sustained heavy fog.Secondly,there is a static and even pressure field around Qiongzhou Strait and the southwest vortex plays an auxiliary role.The oceanic southerly winds resists the dry continental air mass at the boundary layer,which is in favor of maintaining the humidity of the boundary layer.Thirdly,the bottom layer is warm and humid;at the same time,a dry center maintains above the near-surface wet layer at 925 hPa.Such stratification is conducive to the maintenance and formation of sea fog with certain thickness.Fourthly,the increase of low clouds and weak precipitation are important factors for the maintenance of sea fog throughout the day on 18 February.
作者
黄彬
宋晚郊
刘爽
孙舒悦
吴振玲
HUANG Bin;SONG Wanjiao;LIU Shuang;SUN Shuyue;WU Zhenling(National Meteorological Center, Beijing 100081, China;National Satellite Meteorological Center, Beijing 100081, China;Tianjin Meteorological Observatory, Tianjin 300074, China)
出处
《海洋气象学报》
2020年第4期52-59,共8页
Journal of Marine Meteorology
基金
国家重点研发计划“重大自然灾害监测预警与防范”重点专项(2019YFC1510100)。
关键词
卫星监测
海面温度距平
暖湿气流
边界层特征
持续性大雾
海雾
satellite monitoring
sea surface temperature anomaly(SSTA)
warm and moist airflow
boundary layer characteristics
sustained heavy fog
sea fog
