Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Building 3, Courtyard 16, Lincui Road, Chaoyang District, 100101, Beijing, China.
Environ Sci Pollut Res Int. 2015 Feb;22(4):2735-44. doi: 10.1007/s11356-014-3496-1. Epub 2014 Sep 11.
Our research provides the first complete year-long dataset of wet deposition of trace elements in the high Himalayas based on a total of 42 wet deposition events on the northern slope of Mt. Qomolangma (Everest). Except for typical crustal elements (Al, Fe, and Mn), the concentration level of most trace elements (Sc, V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Cs, Pb, Bi, and U) are generally comparable to those preserved in snow pits and ice cores from the nearby East Rongbuk Glacier. Cadmium was the element most affected by anthropogenic emissions. No pronounced seasonal variations are observed for most trace elements despite different transport pathways. In our study, the composition of wet precipitation reflects a regional background condition and is not clearly related to specific source regions. For the trace element record from ice cores and snow pits in the Himalayas, it could be deduced that the pronounced seasonal patterns were caused by the dry deposition of trace elements (aerosols) during their long exposure to the atmosphere after precipitation events. Our findings are of value for the understanding of the trace element deposition mechanisms in the Himalayas.
我们的研究提供了喜马拉雅山高海拔地区微量元素湿沉降的首个完整的长达一年的数据，共采集了珠穆朗玛峰（珠穆朗玛峰）北坡 42 次湿沉降事件。除了典型的地壳元素（Al、Fe 和 Mn）外，大多数微量元素（Sc、V、Cr、Co、Ni、Cu、Zn、As、Mo、Cd、Sn、Cs、Pb、Bi 和 U）的浓度水平一般与附近东绒布冰川的雪坑和冰芯中保存的浓度水平相当。镉是受人为排放影响最大的元素。尽管运输途径不同，但大多数微量元素没有明显的季节性变化。在我们的研究中，降水的成分反映了区域背景条件，与特定的源区没有明显关系。对于喜马拉雅山冰芯和雪坑中的微量元素记录，可以推断出明显的季节性模式是由于降水事件后，微量元素（气溶胶）在长时间暴露于大气中时的干沉降造成的。我们的研究结果对理解喜马拉雅山地区微量元素沉积机制具有重要价值。
