摘要
针对2018年11月23日至12月3日华东地区一次持续性、大范围的雾霾过程,利用地面污染物观测、再分析资料、地面气象观测以及气象探空等,从环流异常、地面气象条件以及边界层结构等方面,分析了本次雾霾过程的气象成因。研究发现:(1)2018年冬季500 hPa亚欧中高纬以纬向环流为主,华北、黄淮位势偏高,冷空气影响偏北。700 hPa孟加拉湾北侧和四川盆地位势偏高,中纬度环流较平,没有形成西低东高有利于水汽输送形势。850 hPa和925 hPa存在偏南风异常,冬季风偏弱,阻碍冷空气南下。环流异常造成气温和湿度偏高、风速和能见度偏低,为污染形成提供了有利的气候背景。(2)冷空气带来的区域输送叠加局地静稳积累是本次雾霾过程的显著特点,不同强度的冷空气对于污染程度和区域的影响具有差异。11月24日和27日两次冷空气较弱,淮河以北受到输送影响,之后均压场控制,地面条件趋于静稳,加剧了污染程度;11月29日冷空气稍强,污染物输送南压至长江以南,后期地面受鞍型场控制,表现出风速小、湿度高、能见度低的特征,污染范围和程度都达到峰值。(3)在污染发展和高峰阶段,边界层均为逆温或等温层结,整层均受到高湿和小风的控制,不利于污染物垂直扩散,加剧污染事件的发展。
A persistent and wide range fog and haze event happened in the eastern China during 23 November and 3 December 2018.Using air pollution observation,surface meteorological data,sounding data and ERA-Interim reanalysis data,meteorological formation mechanism of the pollution event was discussed in climate anomaly,surface weather condition and planetary boundary layer structure.The results show:(1)At 500 hPa,midhigh latitudes of Eurasia were dominated by zonal circulation and abnormal high existed at North China and Huanghuai regions,which leaded to cold air northward.Meanwhile,anomalous high at 700 hPa was found both at Sichuan Basin and north of Bay of Bengal,which smoothed latitude circulation and was unfavorable for more water vapor transported to eastern China.The anomalous southerly winds at 850 hPa and 925 hPa resulted in a weak East Asian winter monsoon and resisted cold air moving southward.All the circulation anomalies caused abnormal surface meteorological conditions(high temperature,high relative humidity,weak wind,low visibility)and provided a favorable climate background for air pollution formation.(2)The remarkable feature for the air pollution event was the joint role by regional transmission and the local stagnant meteorological situation.Different intensities of cold air had different effect for pollution level and area.In 24 and 27 November,regional transmission just can affect the north area of the Huaihe River with northerly wind under weak cold air.Then it was controlled by uniform pressure field and the ground conditions tended to be stable,which aggravated the pollution level.In 29 November,the cold air was strengthened and air pollution transportation could cross the Yangtze River.Then the ground was controlled by saddle field,showing the characteristics of low wind speed,high humidity and low visibility.Thus,this air pollution reached the peak value.(3)The structure of boundary layer can inhibit the vertical transport of air pollutants.During the development and peak stage of air pollution,there were inversion or isothermal layer and the whole layer is controlled by high humidity and breeze,which is not conducive to the vertical diffusion of pollutants.
作者
周述学
邓学良
王传辉
姚叶青
丁鹤鸣
杨开围
ZHOU Shuxue;DENG Xueliang;WANG Chuanhui;YAO Yeqing;DING Heming;YANG Kaiwei(Anhui Institute of Meteorology,Key Laboratory of Atmospheric Science and Satellite Remote Sensing,Hefei 230031,Anhui,China;Shouxian national climatology observatory,Shouxian 232200,Anhui,China;Typical ecological meteorological field science experimental base of Huaihe River Basin of China Meteorological Administration,Shouxian 232200,Anhui,China;Anhui Public Meteorological Service Center,Hefei 230031,Anhui,China;Fuyang Meteorological Bureau,Fuyang 236000,Anhui,China;Hefei Meteorological Bureau,Hefei 230031,Anhui,China)
出处
《高原气象》
CSCD
北大核心
2020年第5期1110-1121,共12页
Plateau Meteorology
基金
安徽省公益性研究联动计划项目(1604f0804003)
国家自然科学基金项目(41875171)
安徽省重点研究与开发项目(1804a0802215)。
关键词
华东地区
雾霾
气象条件
Eastern China
fog and haze
meteorological conditions
