干旱气象

• 论文 • 上一篇    下一篇

西安地区一次重污染过程的气象条件及轨迹分析

杨晓春1杜萌萌1吴其重2程龙1毕旭1翟园1   

  1. 1.陕西省西安市气象局,陕西西安710016;2.北京师范大学全球变化与地球系统科学研究院,北京100875
  • 出版日期:2016-06-30 发布日期:2016-06-30
  • 作者简介:杨晓春(1984-),女,汉族,陕西安塞人,硕士,工程师,主要从事天气气候、数值模拟研究. E-mail: y_xiaochun@sina.com
  • 基金资助:

    国家自然科学基金青年科学基金(41305121)及陕西省气象局预报员专项(2015Y-17)共同资助

Analysis on Meteorological Condition and Trajectory of a Serious Pollution Weather in Xi’an of Shaanxi

YANG Xiaochun 1, DU Mengmeng 1, WU Qizhong2, CHENG Long 1, BI Xu1, ZHAI Yuan1   

  1. 1. Xi’an Meteorological Bureau of Shaanxi Province, Xi’an 710016, China;2. College of Global
    Change and Earth System Science (GCESS), Beijing Normal University, Beijing 100875, China
  • Online:2016-06-30 Published:2016-06-30

摘要:

利用西安市气象常规观测资料、美国国家环境预报中心(NCEP)1°×1°再分析资料FNL (Final),对西安地区2012年12月11—15日的一次重污染天气过程进行分析。结果表明:(1)与历史同期常年值比较,此次重污染天气过程中地面气象数据显示出明显的寡照、低温、高湿以及低风速;(2)高压后部的形势与地面弱辐合有利于近地面水汽的输送和凝结,与850 hPa的高湿相互配合,使得水汽与污染物相互吸附加剧污染天气。700 hPa以下明显的下沉气流、持续出现的逆温层结、较低的混合层厚度将污染物聚集于近地面层内,引起污染的持续和加重;(4)西安地区所处的“喇叭口”盆地地形也是重污染天气持续的一个重要原因;(5)后向轨迹模拟结果显示偏东方向的河南、山西、渭南等地区为此次重污染过程中输入污染物的主要来源。

关键词: 重污染天气, 气象条件, 后向轨迹

Abstract:

The weather conditions, atmospheric circulation background, formation mechanism and pollutant trajectory of a heavy air pollution weather occurring from 11 to 15 December 2012 in Xi’an were analyzed based on daily data including air quality observation, the routine weather observation and reanalysis data from NCEP (FNL) with spatial grid 1° × 1°. The results are as follows:(1)Compared with climatological normal, the meterological elements were abnormal from 11 to 15 December 2012 with obviously shorter sunshine hours, lower air temperature, higher relative humidity and weaker surface wind speed. (2)The location of southwest anticyclone and weak convergence near surface benefited transportation and gathering of water vapor and pollutants and cooperated with high humid region of low layer, which provided favorable environmental field for hazy weather and heavy air pollution. In addition, the descending air flows, strong temperature inversion layer, lower mixing layer depth and stable large scale circulation prevented pollutants from diffusing to the upper air. (3)The special geographical condition of Xi’an was an important factor for the lasting of serious pollution. The south and north downdrafts gathered in Xi’an which restrained pollutants from diffusing and aggravated the pollution. (4)The pollutant trajectories simulation indicated that the main pollutants came from the east of Xi’an.

Key words: serious pollution weather, meteorological conditions, backward trajectory

中图分类号: