重庆南川区雾气候特征及天气成因分析  

Analysis on the Climatic Characteristics and Weather Causes of Fog in Nanchuan District of Chongqing

作　　者：任照环 许伟 余蜀豫[1] 黄玉叶 REN Zhaohuan;XU Wei;YU Shuyu;HUANG Yuye(Chonging Lightning Prolection Center,Chongqing 401147,China;Nanchuan Meteorological Bureau,Nanchuan 408400,China)

机构地区：[1]重庆市防雷中心,重庆401147 [2]重庆市南川区气象局,重庆南川408400

出　　处：《成都信息工程大学学报》2021年第2期223-229,共7页Journal of Chengdu University of Information Technology

基　　金：重庆市气象局青年基金资助项目(QNJJ-201507);重庆市气象局智慧气象技术创新团队资助项目(ZHCXTD-201821)。

摘　　要：为深入了解南川区雾的气候特征及天气成因,利用1957-2017年常规气象资料分析南川区雾的气候特征及影响因子。利用NCEP 1°×1°的FNL资料,采用合成分析方法,对典型的锋面雾和辐射雾的天气成因进行分析。研究结果表明:(1)南川区雾日气候平均值为41.6 d/a,20世纪70年代处于少雾期,80-90年代雾日快速增长,进入21世纪初雾日有所回落;(2)雾过程的发生次数随着持续天数的增加呈幂函数形式减少,连续5 d及以上的雾过程占总数的4.8%;(3)雾日数与混合层厚度及平均、最低、最高气温呈负相关;温度露点差低于0.5℃、风速介于2~3 m/s、大气稳定度为中性及较稳定是雾出现的最有利条件;(4)辐射雾发生时,重庆位于500 hPa天气图的槽后脊前,高空受干冷的西北气流控制,地面上高压控制中东部地区,重庆位于均压场之中;锋面雾发生时,500 hPa青藏高原北部有一横槽正在发展,亚洲中纬度地区环流经向梯度较强,青藏高原南部有短波槽活动,地面上高压中心位于蒙古国境内,锋面位于重庆至湖南一带;(5)锋面雾相对湿度场特征为湿层深厚,且中高空有明显的逆湿现象,辐射雾则表现为上干下湿;辐射雾发生时低层有等温层。In order to deeply understand the climatic characteristics and weather causes of fog in Nanchuan District,the climatic characteristics and influence factors of fog in Nanchuan District were analyzed with conventional meteorological data from 1957 to 2017.The weather causes of rain fog and radiation fog in Nanchuan District are analyzed by using synthesis and analysis method and NCEP 1°×1°data.The results show that,the climatic average value of foggy day in Nanchuan District is 41.6 d/a,which was in the period of low fog in 1970’s,and then increased rapidly from 1980 s to 1990 s,and the number of foggy days declined in the early 21 st century;(2)The number of foggy weather processes decreases in the form of exponential function with the increase of continuous days,and foggy processes lasting for 5 days or more account for 4.8%of the total;(3)The number of fog days is negatively correlated with the day-by-day mixed layer depth,the minimum,maximum and average temperature;the temperature dew point difference is less than 0.5℃,the wind speed is 2-3 m/s,the most favorable condition for fog is that the atmospheric stability is neutral and relatively stable;(4)When the radiation fog occurred,Chongqing was located in front of the ridge behind the trough on the 500 hPa weather map,and the high altitude is controlled by the dry and cold northwest air flow;On the ground,the central and eastern China is controlled by high pressure,and Chongqing is located in the uniform pressure field;When the front fog occurred,there was a horizontal trough developing in the northern part of the Qinghai Tibet Plateau on the 500 hPa weather map,the meridional gradient of circulation in the middle latitude of Asia is strong,and the short wave trough was active in the southern part of the Qinghai Tibet Plateau;the center of the surface high pressure was located in Mongolia,and the front was located in the area between Chongqing and Hunan;(5)The relative humidity field of frontal fog is characterized by a thick wet layer,and there is an o

关 键 词：气象学 气候变化 南川 雾 气候特征 合成分析 

分 类 号：P426.4[天文地球—大气科学及气象学]