华北地区一次重污染天气的气象变化过程分析

The Comprehensive Analysis of a Heavy Air Pollution Episode in North China Region in February,2014

利用大气环境监测数据、常规气象观测资料、探空数据以及HYSPLIT后向轨迹模式对2014年2月20—26日发生在华北区域的一次大面积重污染天气进行综合分析。利用风云卫星观测资料直观展示了污染的生成、消散状况。结果表明,在此次重污染天气过程中,华北地区主要城市均观测到高浓度的PM_(2.5),其中北京、石家庄PM_(2.5)小时浓度均值分别为286.1、371.2μg/m^3。该次污染与天气过程关系密切,平稳的高空环流形势、华北地面弱低压为污染天气的发生、发展提供了有利的气象条件。地面的静风或小风天气以及近地逆温的出现有利于污染的维持。后向轨迹分析表明,此次污染过程区域性明显,南部、西南部周边地区的污染物外源性输入对研究的主要城市有显著影响。

A large-area air pollution occurred in North China from Feb,20 to 26,2014 were analyzed using air environmental monitoring data,routine meteorological monitoring data,air sounding data and HYSPLIT mode. The FY monitoring images were also used to demonstrate the generation and dissipation of the pollution. The result shows that during this pollution period,very high concentrations of PM2. 5were observed. The hourly average value of PM2. 5for Beijing and Shijazhuang are as high as 286. 1and 371. 2 μg / m^3,respectively. This pollution event is closely associated with the synoptic situation. The stable high-altitude circulation and weak low pressure near surface in North China are favorable for the occurrence and development of the pollution.The backward trajectory shows that the pollution is of significant regional characteristics and the emissions from south and southwest greatly influenced the cities in this study.