乌鲁木齐黑碳气溶胶浓度时间变化特征及影响因素分析

Analysis on the Time Variation Characteristics and Influencing Foetors of Black Carbon Aerosol Factors in Urumqi

利用乌鲁木齐市环境空气超级站中MAAP-5012型黑碳仪对乌鲁木齐市黑碳气溶胶进行连续一年的监测,并结合乌鲁木齐环境空气质量城市站小时数据和日数据及气象数据对黑碳气溶胶变化情况进行综合分析。结果表明:2019年6月至2020年5月乌鲁木齐黑碳气溶胶浓度日均值为1 506(±1 096) ng/m~3,本底值为575 ng/m~3,与国内主要城市相比黑碳浓度相对较低;污染最严重的冬季黑碳浓度为2 414(±1 325) ng/m~3,本底值为825 ng/m~3,较十年前浓度下降明显。乌鲁木齐市黑碳气溶胶浓度随季节变化差异大,冬季>秋季>夏季>春季,24小时昼夜变化整体呈现"夜高昼低"和不典型的"双峰双谷"特征,"周末效应"特征显著。相关性分析结果表明:乌鲁木齐黑碳气溶胶与NO_2、CO的Pearson相关性系数均超过0.8,一元线性拟合度均超过0.7,黑碳气溶胶与环境空气中的污染物NO_2、CO具有高度的同源性。虽然气象因素中温度、湿度、风速与黑碳的Pearson相关性及一元线性拟合效果不佳,但气象因素仍是影响黑碳气溶胶浓度重要因素。

Using MAAP-5012 black carbon instrument in Urumqi ambient air super station to monitor black carbon aerosol in Urumqi for a year,and combining with the hourly,daily and meteorological data of Urumqi ambient air quality station to comprehensively analyze the change of black carbon aerosol,the results show that:the daily mean concentration of black carbon aerosol from June 2019 to May 2020 in Urumqi is 1506(±1096)ng/m 3,and the background value is 575 ng/m 3,which is relatively low compared with the main cities in China;the worst winter black carbon pollution concentration is 2414(+1325)ng/m 3,background value of 825 ng/m 3,concentration decreased significantly over the past ten years.The significant seasonal variation of black carbon aerosol concentration in Urumqi is winter>autumn>summer>spring.The 24-hour diurnal variation showed the characteristics of“high night and low day”and atypical“double peak and double valley”,and the“weekend effect”is significant.The results of correlation analysis show that the pearson correlation coefficients of Urumqi black carbon aerosol with NO 2 and CO are more than 0.8,and the univariate linear fitting degrees are more than 0.7.The black carbon aerosol has high homology with the pollutants NO 2 and CO in air.Although the pearson correlation and univariate linear fitting between temperature,humidity,wind speed and black carbon are not good,the meteorological factors are still important factors affecting black carbon aerosol concentration.