北极夏季大气气溶胶单颗粒研究

为研究北极地区大气气溶胶颗粒的物理化学特性,于2013年8月8~12日环Svalbard岛收集大气气溶胶样品,利用带能谱的透射电子显微镜(TEM-EDS)共分析2530个单颗粒,并获得颗粒物的形貌特征和化学组成.结果表明,北极地区颗粒物主要表现为5种类型,分别为海盐颗粒、富S颗粒、富Fe颗粒、含碳颗粒和矿物颗粒.后向气流轨迹显示,采样期间大气污染物主要来自于北极点周边的海洋上空和附近格陵兰岛地区.来自海洋上空的大气中主要包含海盐颗粒,所占数量比例为54.7%;经过陆地的大气样品中95.4%为矿物颗粒.利用时间密度因子法估算出北极地区PM2.5质量浓度范围为0.55~0.72mg/m3.

Characteristics of individual aerosol particles in Arctic summer

Samples of individual particle were collected around Svalbard island during 8-12August, 2013. Physicochemical characteristics of 2530 aerosol particles were analysed through transmission electron microscopy (TEM) coupled with an energy-dispersive X-ray spectrometer (EDS). Arctic aerosol particles were classified as five types: sea-salt, S-rich, Fe-rich, carbonaceous and mineral dust particles. Air masses showed either atmospheric circulation in the arctic ocean or transport of air from Svalbard and Greenland. Samples collected under the air mass of the arctic ocean mainly contained sea-salt particles (54.7% of total in the samples). Mineral dust may be transported from the land, because samples of air mass from Svalbard and Greenland were dominated by mineral dust particles (95.4% of total particles in the samples). We estimated the PM2.5 mass concentration ranging from 0.55mg/m3 to 0.72mg/m3 in Arctic atmosphere.