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DOI	10.5194/tc-10-825-2016
	Potential genesis and implications of calcium nitrate in Antarctic snow
	Mahalinganathan K.; Thamban M.
发表日期	2016
ISSN	19940416
卷号	10 期号:2
英文摘要	Among the large variety of particulates in the atmosphere, calcic mineral dust particles have highly reactive surfaces that undergo heterogeneous reactions with atmospheric acids contiguously. The association between nssCa2+, an important proxy indicator of mineral dust, and NO3-, a dominant anion in the Antarctic snowpack, was analysed. A total of 41 snow cores (∼1 m each) that represent snow deposited during 2008-2009 were studied along coastal-inland transects from two different regions in East Antarctica - the Princess Elizabeth Land (PEL) and central Dronning Maud Land (cDML). Correlation statistics showed a strong association (at 99 % significance level) between NO3- and nssCa2+ at the near-coastal sections of both PEL (r = 0.74) and cDML (r = 0.82) transects. Similarly, a strong association between these ions was also observed in snow deposits at the inland sections of PEL (r = 0.73) and cDML (r = 0.84). Such systematic associations between nssCa2+ and NO3- are attributed to the interaction between calcic mineral dust and nitric acid in the atmosphere, leading to the formation of calcium nitrate (Ca(NO3)2) aerosol. Principal component analysis revealed common transport and depositional processes for nssCa2+ and NO3- both in PEL and cDML. Forward- and back-trajectory analyses using HYSPLIT model v. 4 revealed that southern South America (SSA) was an important dust-emitting source to the study region, aided by the westerlies. Particle size distribution showed that over 90 % of the dust was in the range lt; 4 μm, indicating that these dust particles reached the Antarctic region via long-range transport from the SSA region. We propose that the association between nssCa2+ and NO3- occurs during the long-range transport due to the formation of Ca(NO3)2) rather than to local neutralisation processes. However, the influence of local dust sources from the nunataks in cDML and the contribution of high sea salt in coastal PEL evidently mask such association in the mountainous and coastal regions respectively. Ionic balance calculations showed that 70-75 % of NO3- in the coastal sections was associated with nssCa2+ (to form Ca(NO3)2). However, in the inland sections, 50-55 % of NO3- was present as HNO3. The study indicates that the input of dust-bound NO3- contributes a significant fraction of the total NO3- deposited in coastal Antarctic snow. © Author(s) 2016.
学科领域	aerosol; aerosol composition; aerosol formation; anion; calcium; coastal zone; correlation; dust; nitric acid; particulate matter; principal component analysis; sea salt; size distribution; snow; Antarctica; East Antarctica; Princess Elizabeth Land; Queen Maud Land
语种	英语
scopus关键词	aerosol; aerosol composition; aerosol formation; anion; calcium; coastal zone; correlation; dust; nitric acid; particulate matter; principal component analysis; sea salt; size distribution; snow; Antarctica; East Antarctica; Princess Elizabeth Land; Queen Maud Land
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119658
作者单位	National Centre for Antarctic and Ocean Research, Headland Sada, Vasco-da-Gama, Goa, India
推荐引用方式 GB/T 7714	Mahalinganathan K.,Thamban M.. Potential genesis and implications of calcium nitrate in Antarctic snow[J],2016,10(2).
APA	Mahalinganathan K.,&Thamban M..(2016).Potential genesis and implications of calcium nitrate in Antarctic snow.Cryosphere,10(2).
MLA	Mahalinganathan K.,et al."Potential genesis and implications of calcium nitrate in Antarctic snow".Cryosphere 10.2(2016).