2002年北京PM10时间序列及其成因分析

以北京2002年的ρ(PM₁₀₎日平均值和气象要素观测资料为例，根据小波分析的原理，利用Matlab小波分析工具，对逐日ρ(PM₁₀₎时间序列进行分解和重构，分析了该地区ρ(PM₁₀₎的年变化规律和突变特征.结果表明:2002年北京PM₁₀污染季节性变化强，春季最严重，冬季次之，夏、秋季节较好；全年共有4个突变点，均出现在沙尘暴或强沙尘暴期间，并指出沙尘天气是北京ρ(PM₁₀₎发生突变的主要影响因素.在此基础上，根据形成原因及气象资料分析，将2002年PM₁₀重污染天气过程分为沙尘型和排放累积型2类，并阐述了形成各类PM₁₀重污染天气的气象原因. 

Analysis for PM10 Concentration Using Time Series Method and Its Formationin Beijing, 2002

Based on average daily PM10 mass concentrations and meteorological elements of Beijing in 2002, the daily PM10 time series were decomposed and reconstructed, and yearly change trend of PM10 time series and the jump features of the variations analyzed, according to wavelet analysis principle and using Maflab wavelet analysis tool. The results indicated that PM10 pollution has significant seasonal variations in Beijing in 2002; and four mutation points were found, all of which were during the sandstorms or strong sandstorms, and so the dust weather should be the main factor for mutations of PM10 mass concentration. According to the formation and meteorological data, the process of heavy PM10 pollution in 2002 is divided into two types, i.e. dust pollution type and emissions accumulation type. The reasons for formation of the two types were briefly discussed.