The size distribution of atmospheric aerosols together with their composition, sources and sinks, is a key element in understanding aerosol effects on the Earth’s climate. Aerosol particle size distribution and chemical composition were measured over the Southern Ocean and at Antarctic region during December 2009–March 2010. Aerosol samples were collected using multi-stage low volume Air Sampler, and an aerosol size spectrometer was employed to monitor PM mass concentration continuously. The mean mass concentrations for PM10, PM2.5 and PM1 were 1.5, 1.0 and 0.6 μg/m3, respectively at the Bharati station and were almost 2.5 times higher at the Maitri station. The mass size distribution of the aerosols measured by using a low volume air sampler exhibited a bimodal feature with a peak each in the size range of 0.4 to 0.7 μm and 3 to 5 μm. The difference in concentrations between the two locations for fine particles was comparatively lower than that for simultaneously measured coarse particles. Aerosol samples were analyzed for various water-soluble ionic constituents e.g. Na+, K+, Ca2+, Mg2+, NH4+, Cl−, SO42− and NO3−. Sea-salt aerosols contributed to 86% of the measured mass over the Southern Ocean, 80% over Bharati and 76% at Maitri. The Southern Ocean being the most significant source of the particles during summer time, controls the aerosols at Bharati and Maitri sites. The present study will be helpful in simulating atmospheric processes responsible for aerosol characterization over coastal Antarctica and understanding its environmental implications related to radiation budget and climate over this region.

中文翻译：

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南大洋和南极地区夏季气溶胶的粒径分布和化学成分

大气气溶胶的大小分布及其组成、来源和汇，是了解气溶胶对地球气候影响的关键因素。2009 年 12 月至 2010 年 3 月期间在南大洋和南极地区测量了气溶胶粒径分布和化学成分。使用多级低容量空气采样器收集气溶胶样品，并使用气溶胶尺寸光谱仪连续监测 PM 质量浓度. Bharati 站的 PM10、PM2.5 和 PM1 的平均质量浓度分别为 1.5、1.0 和 0.6 μg/m3，几乎是 Maitri 站的 2.5 倍。通过使用低容量空气采样器测量的气溶胶的质量尺寸分布表现出双峰特征，峰值分别在 0.4 至 0.7 微米和 3 至 5 微米的尺寸范围内。细颗粒的两个位置之间的浓度差异比同时测量的粗颗粒的浓度差异要小。分析气溶胶样品的各种水溶性离子成分，例如 Na+、K+、Ca2+、Mg2+、NH4+、Cl-、SO42- 和 NO3-。海盐气溶胶在南大洋的测量质量中占 86%，在 Bharati 占 80%，在 Maitri 占 76%。南大洋是夏季最重要的颗粒来源，控制着 Bharati 和 Maitri 站点的气溶胶。本研究将有助于模拟负责南极洲沿海气溶胶特征的大气过程，并了解其与该地区辐射收支和气候相关的环境影响。