摘要
利用2015和2016年3—5月北京地区和中国背景地区兴隆环境监测站的逐小时环境细颗粒物(PM_(2.5))监测数据和NCEP/NCAR再分析资料,分析北京春季PM_(2.5)的污染特征及相应气象原因.结果表明,北京春季平均PM_(2.5)浓度低于国家空气质量二级标准,并有逐月波动降低的变化特征.北京平均PM_(2.5)浓度约高于兴隆1倍,但污染发生期间,其浓度可高于兴隆数倍;通过对4次污染过程中PM_(2.5)的变化特征与气象条件进行分析可知,500 hPa较平直西风气流或偏西北气流控制下的地面低压场利于PM_(2.5)堆积从而形成污染天气,在此条件下北京各监测站PM_(2.5)浓度增长较为接近,但在高浓度维持期间又可表现出较大差异;高空槽后地面高压东移南下形成有利扩散条件可迅速清除PM_(2.5),在这一条件下,北京PM_(2.5)可降至自然条件下同等浓度水平. 500 hPa低槽与地面低压影响下的偏南风形成华北地区回流引起污染物的地区间输送也是北京污染的一个重要原因,而低槽东移引导的低压降水对PM_(2.5)虽也有较好的清除作用,但其清除作用不如冷空气彻底.
Using the NCEP/NCAR re-analysis data and PM2.5 data of 12 environmental monitoring stations in Beijing and Xinglong in March to May of 2015 and 2016,this paper analyze the characteristics of variation of PM2.5 and the corresponding meteorological reasons in Beijing.The results show as follows in spring,the average PM2.5 was lower than the national air quality standard,and there was a trend to decrease and decrease monthly.The average PM2.5 in Beijing is double than in Xinglong,however,it is much higher during the period of pollution.By analyzing the pollution processes and meteorological conditions,the meteorological conditions under the control of the straight west wind in 500 hPa and the low pressure in surface are favorable for the pollution.The changes of PM2.5 in each station are similar,but it shows great difference during the high concentration period.After the trough,the ground high pressure moves eastward and southward to reduce PM2.5 to the same as natural.Under the influence of low trough,the inter-regional transport of pollutants caused by southerly winds was also an important reason.Precipitation can cause a rebound in concentration,but its clearance effect is not as thorough as cold air.
作者
王茜茜
胡文斌
刘啸然
张鉴达
WANG Qianqian;HU Wenbin;LIU Xiaoran;ZHANG Jianda(College of Resources and Environment Sciences,Hebei Normal University/Key Laboratory of Environmental Change and Ecological Construction of Hebei Province,Shijiazhuang 050024,China;Unit No.96751 of PLA,Dalian 116000,Liaoning China;School of Atmospheric Sciences/Plateau Atmosphere and Environment Key Laboratory of Sichuan Province/Joint Laboratory of Climate and Environment Change,Chengdu University of Information Technology,Chengdu 610225,China)
出处
《河南科学》
2018年第12期1928-1934,共7页
Henan Science
基金
国家自然科学基金(41401562)
河北师范大学自然科学基金重点项目(L2015Q05)
河北省自然科学基金(E2013205067)
中国博士后科学基金(2014M561197)
省高等学校青年拔尖人才计划项目(BJ2014041)
