摘要
利用NECP再分析资料、HMW-8卫星红外4-1通道数据、卫星可见光云图和地面常规观测数据,对2020年3月7—8日渤海海域出现的大范围海雾形成的天气背景和低层温度湿度特征进行分析。结果表明:500 hPa浅槽东移至渤海上空,槽前西南气流为海上输送暖湿空气,槽后弱冷空气在东移过程中受山脉阻挡,沿山脉南下,率先为海面带来的东北向弱冷空气强迫下垫面降温,是导致成雾的重要条件。为研究降温强度对雾区模拟结果的影响,利用WRF模式,对背景场下垫面气温进行敏感性试验,当气温下降6℃时的模拟效果较好,模拟结果在1000 hPa整层降温显著,利于逆温层结形成,同时在相对湿度大值区增加了东北风量,垂直层结降温增湿的位置与观测事实相符,表明此次弱冷空气过程对下垫面温度的降低,有利于低层水汽凝结,使海雾得以发展。
Using NECP reanalysis data,HMW-8 infrared 4-1 channel data,satellite visible cloud image and ground conventional observation data,the characteristics of the weather background and low-level temperature and humidity that causes large-scale sea fog process in the Bohai Sea from March 7 to 8,2020.are analyzed.When the 500 hPa shallow trough moves eastward to the Bohai Sea,the southwest airflow in front of the trough transports warm and humid air to the sea.The weak cold air behind the trough is blocked by the mountains in the process of eastward migration,and moves southward along the mountain range,which first brings the northeast weak cold air to the sea surface.The cold air forces the underlying surface to cool down,which is an important condition for the formation of sea fog.In order to study the influence of cooling intensity on the simulation results of fog area,sensitivity test of the underlying surface temperature of background field is carried out by using WRF model.The simulation effect is reasonably well when air temperature drops by 6℃with significant temperature decreasing in the level of 1000 hPa,which favors the formation of inverse temperature stratification.Meanwhile,the northeast wind volume is increased in the high relative humidity area and the location of the cooling and humidification of vertical stratification is consistent with observation,indicating that the cold air process reduces the temperature of underlying surface,which is conducive to the condensation of low-level water vapor and the development of sea fog.
作者
王锐
刘彬贤
WANG Rui;LIU Bin-xian(Tianjin Ocean Center Meteorological Observatory,Tianjin 300074 China)
出处
《海洋预报》
CSCD
北大核心
2021年第6期82-92,共11页
Marine Forecasts
基金
天津市自然科学基金(19JCYBJC23700)
天津市气象局科研项目(202130ybxm12)
天津市科技计划项目(18ZXAQSF00130)
中国气象局创新发展专项(CXFZ2021J021)。
关键词
冷空气
渤海
海雾
数值模拟
气温敏感性试验
cold air
Bohai Sea
sea fog
numerical simulation
temperature sensitivity test
