北京郊区夏季PM_(2.5)和黑碳气溶胶的观测资料分析

Continuous observation of PM_(2.5) and black carbon aerosol during summer in Beijing suburb

城市近郊常受到城区污染物扩散和输送的影响,2010年7月21日至8月6日利用β射线颗粒物连续监测仪和黑碳仪对北京西北郊区PM2.5和黑碳气溶胶(BC)进行了连续观测。结果表明,北京西北郊区夏季PM2.5和BC的质量浓度分别是(133.16±81.64)、(2.89±1.62)μg/m3。受明显的山谷风的影响,来自观测点东南方的城区的气流使PM2.5和BC浓度升高,来自观测点西北方向的风则使PM2.5和BC浓度降低。受局地排放、区域输送和气象条件的共同影响,郊区的PM2.5和BC浓度表现出明显日变化特征,二者浓度在上午、傍晚和夜间显著上升。

β-ray continuous ambient particulate monitor and aethalometer were employed to investigate the pollution characteristics of PM2.5 and the black carbon aerosol（BC）at a northwest suburban site of Beijing from July 21 to August 6,2010.The results indicated that the mass concentration of PM2.5 and BC were（133.16±81.64）μg/m3 and（2.89±1.62）μg/m3,respectively.Affected by the obvious mountain-valley wind,the mass concentration of PM2.5 and BC increased when the contaminated air came from Beijing urban areas,which located in southeast of the observation place,and decreased when the relatively sanitary airflow came from mountain areas,which located in northwest of the observation place.The mass concentrations of PM2.5 and BC displayed obvious diurnal variation characteristics and significantly increased during forenoon,nightfall and night due to local emissions,regional transportation and meteorological conditions.