气象条件与成都市空气质量的关系研究

Abstract

利用2007~2016年成都市常规地面气象观测资料、探空资料以及2015~2016年空气质量指数监测资料，分析了成都市空气质量变化的特征，探讨了气象要素与空气质量之间的关系，结果表明：成都市空气质量以优良或轻度污染为主，空气污染冬季最重，夏季最轻。市内常年盛行偏北风，风速较小，静风频率高，对污染的扩散十分不利；当日降水量大于0.5mm时，对空气质量有明显的改善作用；空气质量还与气温、气压、能见度、日照等气象要素有显著的相关关系。因中性类天气条件出现频率较高，所以大气稳定度对空气质量作用具有不确定性，此时合适的逆温层高度和强度可以作为判定空气质量的重要依据。当逆温层高度低于933hpa，逆温强度大于2.2℃时，污染难以扩散。另外，显著的城市热岛效应有利于大气污染扩散，对改善市区空气质量有一定作用。 This paper studied the characteristics of air pollution of Chengdu and the relationship between air quality and meteorological condition by using the air quality index form 2015-2016 and normally ground meteorological data and sounding data from 2007-2016 of Wen Jiang station. The results show that good air quality or lightly polluted air primarily occurred in Chengdu and the serious air pollution usually occurs in winter; in summer, air pollution is the lightest. North wind is the prevailing wind, wind speed is low, and calm wind frequency is high. These are unfavorable for the pollution dispersion. It showed that when daily precipitation > 0.5 mm, the air quality will be improved evidently. Meanwhile, air quality of Chengdu is significantly correlated with temperature, pressure, visibility and sunshine duration. For neutral weather conditions occur frequently, atmospheric stability is nearly impossible to decide air quality, unless appearing coordinate with temperature inversion. When inversion height is lower than 933 hpa and the intensity of inversion > 2.2˚C, the air pollution is difficult to spread. What’s more, significant urban heat island effect is conducive to the diffusion of air pollution, which has a certain effect on improving air quality in urban areas.