上海市2002年以来空气中可吸入颗粒物浓度变化特征

Feature Change of PM10 Concentration in the Air of Shanghai since 2002

用时间序列的时域分析和频域分析法,探讨2002～2004年空气中可吸入颗粒物(PM10)浓度的频谱和趋势.结果表明PM10的浓度呈周期性变化,而且是由三个周期成分构成;即每年有一次周期性升高的慢周期变化,每周有变化一次的周期和每周变化二次的周期.其浓度呈波动下降的趋势;在2002年较高,2003有一定下降,而在2004年又有呈上升波动的趋势,但其值仍远低于2002年的水平,由此可以说明PM10浓度已得到了较好的控制.

The frequency spectrum and the trend of the concentration of particulate matter less than or equal to 10 microns （PM10） in the air from 2002 to 2004 by using the method of time domain analysis and frequency domain analysis of time series are explored. The results indicate that the periodic change in PM10 appears,and it is composed of 3 period compositions： the slow period to go up periodically once annually, the period to change once every week and the period to change twice weekly. The moving average concentration of PM10 by a year appears with wavy and down trend,rather high in 2002,lower in 2003,a bit higher in 2004 than in 2003, but much lower than in 2002. Thus it shows that concentration of PM10 is controlled well.