弱冷空气引起渤海湾大风的时空分布特征及环境条件分析  

Spatial and temporal distribution characteristics and environmental conditions of gales caused by weak cold air over the Bohai Bay

作　　者：孙晓磊 张唯 胡田田 朱男男 SUN Xiaolei;ZHANG Wei;HU Tiantian;ZHU Nannan(Tianjin Key Laboratory for Oceanic Meteorology,Tianjin 300074,China;Tianjin Ocean Center Meteorological Observatory,Tianjin 300074,China;Hebei Cangzhou Meteorological Bureau,Cangzhou 061001,China)

机构地区：[1]天津市海洋气象重点实验室,天津300074 [2]天津海洋中心气象台,天津300074 [3]河北省沧州市气象局,河北沧州061001

出　　处：《海洋预报》2022年第6期44-54,共11页Marine Forecasts

基　　金：国家重点研发计划(2019YFC1510105);天津市应用基础与前沿技术研究计划(青年项目)(16JQNJC07500);环渤海区域科技协同创新基金项目(QYXM201808)。

摘　　要：根据渤海湾区域地面自动站、浮标站和海上平台站记录,选取2014—2019年11月—次年3月由典型弱冷空气引起的大风个例,进行时空分布特征、区域盛行风、影响系统分型和预报因子统计分析。结果表明:弱冷空气引起的大风较多出现在1月、3月和12月,下午—傍晚易出现强风过程;冷涡后部西北气流型、低槽东移型和高空槽型是形成渤海湾地区弱冷空气大风过程的3种主要天气形势;最大Eady增长率变化趋势与大风的开始与结束时间有很好的对应关系;该类天气的动力对流层顶偏低,主要位于300~400 hPa,高位涡一般伸展至500~700 hPa,配合700 hPa以下的干绝热直减率层结条件,有利于动量下传。Based on the records of automatic ground stations,buoy stations and offshore platform stations in the Bohai Bay area,we select individual cases of gale caused by typical weak cold air between November and March of the following year from 2014 to 2019,and statistically analyze the spatial and temporal distribution characteristics,regional prevailing wind,type of influence system and prediction factors.The results show that the gales caused by weak cold air mostly occurs in January,March and December,especially from afternoon to evening.The northwest flow pattern behind the cold vortex,the low trough moving eastward and the high trough pattern are three main weather conditions for the formation of weak cold air gale in the Bohai Bay area.The variation trend of the Eady growth rate corresponds well with the start and end time of the gale.The dynamic tropopause of this type of weather is low,which is mainly located at 300~400 hPa,and the high vortex generally extends down to 500~700 hPa.Combined with the lamination condition of dry adiabatic lapse rate below 700 hPa,it is conducive to the downward momentum transportation.

关 键 词：弱冷空气 动量下传 最大Eady增长率 

分 类 号：P732.1[天文地球—海洋科学]