一次弱冷空气对渤海海雾影响的数值模拟研究

本文转自：国家海洋预报台

文章图片

文章图片

文章图片

文章图片

一次弱冷空气对渤海海雾影响的数值模拟研究
读书小笔记
单位：天津市气象局天津海洋中心气象台, 天津 300074
分类号：P732.1
出版年·卷·期（页码）：2021·38·第六期（82-92）
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1 000 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。
关键词：冷空气渤海海雾数值模拟气温敏感性试验
Abstract：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.
Key words：cold air; Bohai Sea; sea fog; numerical simulation; temperature sensitivity test

文章图片

文章图片

读者也可以通过公众号菜单栏
“相关知识”板块进入《当期目录》和《过刊浏览》
查阅详细期刊内容
未来两天海洋环境预报
预计明天，
渤海、黄海有0.7到1.2米的轻浪；
东海北部有1.4到2米的中浪；
东海南部、钓鱼岛附近海域有1.9到2.4米的中浪区；
台湾海峡、台湾以东洋面、南海北部、巴士海峡有2.2到2.8米的中浪到大浪区；