Wet precipitation chemistry at a high-altitude site (3,326 m a.s.l.) in the southeastern Tibetan Plateau
Wet precipitation chemistry at a high-altitude site (3,326 m a.s.l.) in the southeastern Tibetan Plateau
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DOI：
10.1007/s11356-012-1379-x
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发表时间：
2013-07-01
影响因子：
5.8
通讯作者：
Cong, Zhiyuan
中科院分区：
文献类型：
--
作者：
Liu, Bin;Kang, Shichang;Cong, Zhiyuan
本文报道了2009年9月至2010年8月青藏高原东南部高海拔林区湿降水化学的观测结果。PH在6.25~9.27之间的碱性湿降水是大气中和沙尘作用的结果。主要离子和微量元素的湿沉积水平与世界各地其他高山和偏远地区大致相当。然而，微量元素(V、Co、Ni、Cu、Zn和Cd)的含量/通量明显高于世界中部和南部的TP和原始地点，反映了潜在的人为干扰。Na+和Cl-的摩尔浓度几乎相等，且呈良好的线性关系，表明有重要的海盐来源，并通过不同来源的计算得到了证实。除Al和Fe外，结壳矿物粉尘占总化学成分的比例较小(<15%)，而大部分物种(不含Na+、Cl-、Mg2+、Al和Fe)主要来源于人类活动。冬季和春季观测到的As-K+(人为来源钾)、As-SO4(2-)和As-NO3(-)的高值表明，这两个季节生物质燃烧和化石燃料燃烧的影响很大，这与南亚灰霾层爆发的时间相吻合。大气环流对湿沉降中的化学成分有显著影响。主要来自孟加拉湾的海洋气团为化学成分提供了大量的海盐，而夏季季风季的微量元素则受到南亚工业排放的很大影响。NH4(+)-N和NO3(-)-N的湿沉降通量分别为1.12 kg N ha(-1)a(-1)和0.29 kg N ha(-1)a(-1)。大气氮的总沉降量估计为6.41千克N公顷(-1)年(-1)，这意味着对该地区高山生态系统的潜在影响。
This paper presents the results of wet precipitation chemistry from September 2009 to August 2010 at a high-altitude forest site in the southeastern Tibetan Plateau (TP). The alkaline wet precipitation, with pH ranging from 6.25 to 9.27, was attributed to the neutralization of dust in the atmosphere. Wet deposition levels of major ions and trace elements were generally comparable with other alpine and remote sites around the world. However, the apparently greater contents/fluxes of trace elements (V, Co, Ni, Cu, Zn, and Cd), compared to those in central and southern TP and pristine sites of the world, reflected potential anthropogenic disturbances. The almost equal mole concentrations and perfect linear relationships of Na+ and Cl- suggested significant sea-salts sources, and was confirmed by calculating diverse sources. Crust mineral dust was responsible for a minor fraction of the chemical components (less than 15 %) except Al and Fe, while most species (without Na+, Cl-, Mg2+, Al, and Fe) arose mainly from anthropogenic activities. High values of as-K+ (anthropogenic sources potassium), as-SO4 (2-), and as-NO3 (-) observed in winter and spring demonstrated the great effects of biomass burning and fossil fuel combustion in these seasons, which coincided with haze layer outburst in South Asia. Atmospheric circulation exerted significant influences on the chemical components in wet deposition. Marine air masses mainly originating from the Bay of Bengal provided a large number of sea salts to the chemical composition, while trace elements during summer monsoon seasons were greatly affected by industrial emissions from South Asia. The flux of wet deposition was 1.12 kg N ha(-1) year(-1) for NH4 (+)-N and 0.29 kg N ha(-1) year(-1) for NO3 (-)-N. The total atmospheric deposition of N was estimated to be 6.41 kg N ha(-1) year(-1), implying potential impacts on the alpine ecosystem in this region.