重庆市CO浓度特征及潜在源分析

Analysis of Carbon Monoxide Concentration Characteristics and Potential Sources in Chongqing

该文基于2018-2020年重庆市空气质量监测网络数据,分析了城市站、区域站和交通站CO浓度水平、时间变化规律,研究了CO与大气污染物、气象参数的相关性,并利用Meteoinfo软件对抵达重庆市各片区的轨迹进行聚类分析、潜在源贡献因子分析及浓度权重分析,获得了各片区CO的传输规律及潜在源区贡献特征。结果表明,2018-2020年,城市站和区域站CO质量浓度为下降趋势,交通站呈现上升趋势,CO质量浓度月变化为“U型”特征,日变化为“双峰”特征,区域站峰值时间晚于城市站和交通站,各类型站点均存在明显“周末效应”。城市站CO与其他大气污染物相关性整体强于区域站,交通站CO与其他大气污染物相关性最低。CO质量浓度与风速为负相关关系,与地面气压和温度的相关性不明显。重庆市冬季的气团轨迹主要来自偏东区域,占比70%以上,此外还有少量轨迹较短的偏西区域轨迹,对应CO质量浓度较高。中心城区主要源区位于重庆主城都市区以及川东城市,主城新区主要源区位于重庆主城都市区、泸州、广安、南充,渝东北片区主要源区位于渝东北区域、川东及湖北省恩施州、湖南省张家界等,渝东南片区主要源区来自渝东南片区及湖北省恩施州。

Based on the data from the Chongqing air quality monitoring network from 2018 to 2020,the CO concentration level and time change law of urban stations,regional stations and transportation stations are analyzed.The correlation between CO and atmospheric pollutants,and the correlation between CO and meteorological parameters are studied.Using Meteoinfo software,cluster analysis,potential source contribution function and concentration weighted trajectory were performed on the trajectories arriving in each area of Chongqing,and the CO transmission law and potential source area contribution characteristics of each area were obtained.The results show that the concentration of CO in urban and regional stations is on a downward trend,while the concentration of CO in traffic stations is on an upward trend.The monthly change of CO mass concentration is a"U-shaped"characteristic.The daily variation of CO mass concentration has a"double peak"feature,and the peak time of regional stations is later than that of urban stations and traffic stations.The CO mass concentration of all types of sites has obvious"weekend effect".The correlation between CO at city stations and other air pollutants is stronger than that at regional stations,and the correlation between CO at traffic stations and other air pollutants is the lowest.The mass concentration of CO is negatively correlated with wind speed,and has no obvious correlation with ground pressure and temperature.The air mass trajectories in Chongqing in winter mainly come from the easterly region,accounting for more than 70%.In addition,there are a few shorter trajectories in the westward region,corresponding to higher CO mass concentrations.The main source areas of the central city are located in the main urban area of Chongqing and the eastern Sichuan city.The main source areas of the main city new area are located in the main city metropolitan area of Chongqing,Luzhou,Guang’an and Nanchong.The main source areas of the northeastern part of Chongqing are located in the northeastern part of Chongqing,eastern Sichuan,Enshi Prefecture in Hubei Province,and Zhangjiajie in Hunan Province.The main source areas of the southeast area of Chongqing are from the southeast area of Chongqing and Enshi Prefecture,Hubei Province.