阿克达拉大气本底站黑碳浓度特征和潜在源

The concentration characteristics and sources of black carbon at the atmospheric background station, Akedala

利用阿克达拉大气本底站2011~2017年黑碳气溶胶(BC)逐小时质量浓度资料和同期气象数据,采用后向轨迹聚类分析、潜在来源贡献函数法(PSCF)和浓度权重轨迹分析法(CWT),研究了阿克达拉站BC不同时间尺度浓度特征和潜在源区.结果表明:阿克达拉站2011~2017年BC呈波动下降趋势,BC清洁程度较高;BC浓度呈春冬高,夏秋低的季节变化特征,春季(398.85±189.35)ng/m^(3)>冬季(389.89±105.94)ng/m^(3)>夏季(272.07±90.07)ng/m^(3)>秋季(269.52±68.07)ng/m^(3),自然因素为BC浓度变化的主要原因;日变化特征表现为白天低、夜间高,基本呈单峰分布;阿克达拉站BC潜在源随季节变化差异明显,后向轨迹,WPSCF和WCWT分析都表明,春季潜在源集中于俄罗斯南部与新疆交界处的阿尔泰山北麓,秋季潜在源为新疆北疆经济带,冬季BC多受境外排放源影响.BC污染控制需要区域环境合作,实现联防联治,尤其是加强跨境污染源监测工作.

In this paper,the concentration features and potential sources of black carbon aerosols(BC)at different time scales at Akedala Atmospheric Background Station were studied by utilizing the hourly mass concentration data of BC at Akedala station from 2011 to 2017 and the meteorological data during the same period.Moreover,the backward-trajectory cluster analysis method,the potential source contribution function(PSCF)method as well as the concentration-weight trajectory analysis(CWT)method were also applied.The results show that BC at Akedala Station presented a fluctuating decreasing trend from 2011 to 2017 with a high level of BC cleanliness.The seasonal variation of BC concentration was characterized as high in spring and winter,and low in summer and autumn with a trend of spring(398.85±189.35ng/m^(3))>winter(389.89±105.94ng/m^(3))>summer(272.07±90.07ng/m^(3))>autumn(269.52±68.07ng/m^(3)).Natural factors were the main causes of BC concentration variation.Moreover,the daily variation of BC concentration was characterized as low in the daytime and high in the nighttime,basically showing a single-peaked distribution.The potential sources of BC at Akedala Station varied significantly with the seasons.According to the analyses by employing the backward-trajectory clustering analysis method,WPSCF as well as WCWT,the potential sources of BC in spring concentrated in the northern foot of the Altai Mountain at the border between southern Russia and Xinjiang,those in autumn were in the economic zone of northern Xinjiang,and BC in winter was influenced mainly by foreign emission sources.Therefore,control of BC pollution requires regional environmental cooperation to achieve joint prevention and control,especially to strengthen the monitoring on cross-border pollution sources.