Nitrogen Speciation and Isotopic Composition of Aerosols Collected at Himalayan Forest (3326 m a.s.l.): Seasonality, Sources, and Implications
Nitrogen Speciation and Isotopic Composition of Aerosols Collected at Himalayan Forest (3326 m a.s.l.): Seasonality, Sources, and Implications
复制标题
喜马拉雅森林 (3326 m a.s.l.) 收集的气溶胶的氮形态和同位素组成：季节性、来源和影响
DOI：
10.1021/acs.est.9b03999
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发表时间：
2019
影响因子：
11.4
通讯作者：
Cong Zhiyuan
中科院分区：
文献类型：
--
作者：
Bhattarai Hemraj;Zhang Yan-Lin;Pavuluri Ch;ra Mouli;Wan Xin;Wu Guangming;Li Peilin;Cao Fang;Zhang Wenqi;Wang Yongjie;Kang Shichang;Ram Kirpa;Kawamura Kimitaka;Ji Zhenming;Widory David;Cong Zhiyuan
Nitrogenous aerosols are ubiquitous in the environment and thus play a vital role in the nutrient balance as well as the Earth’s climate system. However, their abundance, sources, and deposition are poorly understood, particularly in the fragile and ecosensitive Himalayan and Tibetan Plateau (HTP) region. Here, we report concentrations of nitrogen species and isotopic composition (δ15N) in aerosol samples collected from a forest site in the HTP (i.e., Southeast Tibet). Our results revealed that both organic and inorganic nitrogen contribute almost equally with high abundance of ammonium nitrogen (NH4+–N) and water-insoluble organic nitrogen (WION), contributing ∼40% each to aerosol total nitrogen (TN). The concentrations and δ15N exhibit a significant seasonality with ∼2 times higher in winter than in summer with no significant diurnal variations for any species. Moreover, winter aerosols mainly originated from biomass burning emissions from North India and East Pakistan and reached the HTP through a long-range atmospheric transport. The TN dry deposition and total deposition fluxes were 2.04 kg ha–1yr–1and 6.12 kg ha–1yr–1respectively. Our results demonstrate that the air contamination from South Asia reach the HTP and is most likely impacting the high altitude ecosystems in an accepted scenario of increasing emissions over South Asia.
