摘要
该文应用常规气象观测资料、空气污染监测资料和NCEP/NCAR 1°×1°网格点逐6 h再分析资料,对2020年1月20-27日咸阳一次持续性雾霾天气过程的污染实况、静稳指数、混合层高度、环流背景等方面进行分析,结果表明:(1)发生持续性雾霾天气时,咸阳南部各县区空气质量均达到重度-严重污染,空气污染主要是由PM_(2.5)造成,PM_(2.5)浓度连续3 d超过日均五级标准限值,多个县区PM_(2.5)逐时浓度的相关系数在0.83~0.97之间,同步出现了持续污染;(2)咸阳地区地面较小的风速不利于污染物的水平扩散,同时动力条件和水汽条件的相互配合,使雾霾天气得以维持和发展;(3)静稳指数对重污染天气的发生、发展、维持和消散有一定的预报指示意义,通常情况下高PM_(2.5)对应高静稳指数,两者之间呈显著的正相关关系;(4)混合层高度和PM_(2.5)浓度呈显著的负相关,持续较低的混合层高度和较弱的垂直上升运动抑制了近地面层大气垂直风向的湍流交换,不利于污染物在垂直方向上扩散。
Based on conventional meteorological observation data,air pollution monitoring data and NCEP/NCAR 1°×1°grid point reanalysis data for 6 hours,the actual pollution situation,Static stability index,mixing layer height,circulation background and other aspects of the persistent haze weather process in Xianyang on January 20-27,2020 are analyzed.The results showed that:(1)When persistent haze weather occured,the air quality of all counties and districts in the south of Xianyang reached the level of severe pollution to severe pollution.The air pollution was mainly caused by PM_(2.5),The PM_(2.5)concentration exceeded the daily average level 5 standard limit for three consecutive days,and the correlation coefficient of PM_(2.5)hourly concentration in several counties and districts ranges from 0.83 to 0.97,and continuous pollution occured at the same time.(2)In Xianyang area,the relatively small wind speed on the ground was not conducive to the horizontal diffusion of pollutants.Meanwhile,the coordination of dynamic conditions and water vapor conditions enabled the haze weather to be maintained and developed.(3)Static stability index had a certain predictive significance for the transmission,development,maintenance and dissipation of heavy pollution weather.Generally,high PM_(2.5)corresponds to high static stability index,and there was a significant positive correlation between the two.(4)There was a significant negative correlation between the mixing layer height and PM_(2.5)concentration.The continuous low mixing layer height and weak vertical upward movement inhibited the turbulent exchange of vertical wind direction in the near surface atmosphere,which was not conducive to the vertical diffusion of pollutants.
作者
高萌
刘帆
刘艳
王瑾婷
谢逸雯
GAO Meng;LIU Fan;LIU Yan;WANG Jinting;XIE Yiwen(Xianyang Meteorological Bureau,Xianyang 712000,China;Key Laboratory of Eco-Environmental Meteorology for Qinling Mountains and Loess Plateau,Shaanxi Meteorological Bureau,Xi’an 710014,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2021年第S02期71-80,共10页
Environmental Science & Technology
基金
咸阳市气象局重点科研项目(XY2019-006)
关键词
持续性雾霾
天气形势
静稳指数
混合层高度
persistent haze
weather situation
static stability index
mixing layer height
作者简介
高萌(1989-),女,工程师,硕士,研究方向为短期天气预报研究,(电子信箱)gao_xmeng@163.com;通讯作者:刘帆,(电子信箱)liufan2nuist@126.com。
