气象因素对汉中市城区空气污染的影响

目的探讨气象因素对汉中市城区空气污染的影响。方法以汉中市城区2015年1—12月空气质量监测数据和气象资料为基础,分析温度(T)、露点温度(T_d)、平均海平面大气压(P)等气象因素对空气质量的影响及其空气污染特征。结果 AQI及各污染物浓度可用二次函数很好地拟合,拟合曲线的拐点横坐标出现在6月上旬至7月上旬。相关性分析表明,汉中市城区空气质量主要与PM_(2.5)和PM_(10)浓度有关,且PM_(10)大多由PM_(2.5)贡献;PM_(2.5)浓度受到T、水平大气压(P_0)、P、Td的影响较明显,而受气压趋势(P_a)、湿度(U)的影响较小。T_d对PM_(10)浓度的影响高于PM_(2.5)。对于同一大气污染物而言,P的影响高于P0和Pa。各污染物浓度和气象因素之间存在明显的共线性,PM_(2.5)与其他大气污染物及T、P、T_d所构建的主成分回归模型拟合优度较好且无多重共线性。结论汉中市城区气象因素与空气污染存在一定的关联。

Relationships between meteorological parameters and criteria air pollutants in Hanzhong

Objective To understand the influence of meteorological factors on air quality and the characteristics of air pollution in Hanzhong city.Methods The real-time environment air quality data (such as PM10,PM2.5,sulfur dioxide,nitrogen dioxide,ozone,carbon monoxide and air quality index) and air quality index (AQI) of four stations for monitoring ambient air quality and meteorological data,such as temperature (T),dew point temperature (Td),the atmospheric pressure of mean sea level (P) and so on,in Hanzhong in January 1,2015-December 31,2015 were used.Results AQI and air pollutions fitted with quadratic functions well,and the horizontal coordinates of inflection points of quadratic functions usually appeared in early June to early July.The correlation analysis showed that,the dominant factors of air quality in Hanzhoung city were PM2.5 and PM10,and PM10 was mostly contributed by PM2.5,and the correlation analysis between air pollutions and meteorological data suggested that,the concentration of PM2.5 was obviously affected by T,P0,P and Td,but little by Pa and U.As the influence of Td on the aggregation of particles,the correlation coefficient between Td and PM10 was usually higher than that between Td and PM2.5.It was also found that the correlation coefficient between P and air pollutants was usually higher than that between P0,Pa and air pollutants.At last,the principal component regression model was established between PM2.5 and PM10,sulfur dioxide,nitrogen dioxide,ozone,carbon monoxide,temperature (T),dew point temperature (Td),the atmospheric pressure of mean sea level (P),which showed better goodness of fit with no multiple collinearity.Conclusion There is a certain correlation between meteorological factors and air pollution in Hanzhong.