基于PMF模式的北京大气污染特征分析

The Analysis of Beijing Atmospheric Pollution Characteristics by Positive Matrix Factorization

本文利用PMF模型对北京大气污染进行源解析,进一步分析了北京大气污染特征.针对2000~2005年北京大气污染变化趋势,文章选取了3个主因子,分析结果显示：第一主因子代表北京大气燃烧源型污染,主要污染物为NOX、SO2、CO,污染存在明显的季节变化,以秋、冬季较为严重,年际变化大,整体来看,从2000~2005年,燃烧源型污染有减轻的趋势;第二主因子代表地壳源型污染,以极端气候条件下地壳运动产生的大气颗粒物为主,北京春季容易发生沙尘天气,污染最严重,地壳源型污染年际变化复杂,2000~2002年北京沙尘天气频繁发生,地壳源型污染严重,2003年北京沙尘天气少,污染比较轻,2004和2005年,北京地壳源型污染较2000~2002年减轻;第三主因子代表光化学二次污染,主要特征污染物为O3,北京光化学二次污染夏季最严重,年际变化不大.

This study made a source apportionment of Beijing atmospheric pollution by PMF model and focused on Beijing atmospheric pollution characteristics.Three major factors were chosen according to Beijing atmospheric pollution variation trend from 2000 to 2005.The result showed the first factor on behalf of the combustion source pollution,the major pollutants were NO_X,SO_2,CO.The seasonal change of pollution was obvious and getting heavier in fall and winter,the pollution showed a tendency of declining from 2000 to 2005.The second factor on behalf of the earth＇s crust source pollution,the major pollutants were particles from the movement of sand blown by wind under extreme climatic condition,it mostly happened in spring in Beijing and showed complex inter-annual variation.From 2000 to 2002,frequent sand-dust weather processes resulted in high earth＇s crust source pollution,and the pollution got down because of less sand-dust day in 2003;the pollution in 2004 and 2005 was lower than that from 2000 to 2002.The third major factor on behalf of the photochemical pollution,the primary pollutant was O_3,the pollution was heaviest in summer,it had no obvious inter-annual variation.