基于观测与模型模拟的青藏高原大气汞湿沉降时空特征研究

项目名称： 基于观测与模型模拟的青藏高原大气汞湿沉降时空特征研究

项目编号： No.41201057

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地理学

项目作者： 黄杰

作者单位： 中国科学院青藏高原研究所

项目金额： 28万元

中文摘要： 汞是一种具有特殊物理化学性质的有毒重金属元素和全球性污染物。汞主要通过大气沉降进入地表，对地表生态系统构成潜在威胁。作为大气沉降的重要途径，大气降水是汞参与生物地球化学循环的关键环节。目前大气降水汞研究多集中在全球人类密集区，且缺乏对不同形态汞的分析。青藏高原人类活动非常稀少，是全球开展大气降水汞研究的理想背景地区，然而相关研究仍未展开。本项目拟在青藏高原不同区域选取8个野外台站连续收集大气降水样品，测试其不同形态汞(总汞、活性汞、溶解态汞、颗粒态汞和甲基汞)的浓度，并结合降水等其他参数阐明大气汞湿沉降的时空特征及其影响因素；通过汞的实测数据对GEOS-Chem模型进行验证和改进，并利用该模型深入认识青藏高原大气汞湿沉降的时空特征。本研究的开展有望提升青藏高原大气降水汞的研究水平，不仅为评估该区汞沉降潜在的环境风险提供了基础数据，也为全面理解全球汞的生物地球化学循环提供有益参考。

中文关键词： 青藏高原；大气汞沉降；GEOS-Chem模型；时空特征；

英文摘要： Mercury(Hg) is a toxic heavy metal and a global pollutant with special physical and chemical properties. The wet Hg deposition plays a very important role for the entrance of atmospheric Hg to earth surface, and thus may constitute a menace to terrestrial ecosystem. As an environmental media between atmosphere and terrestrial ecosystem, precipitation is regarded as a key process in global Hg biogeochemical cycling. To date, most research on Hg in precipitation were among areas strongly influenced by anthropogenic activities, however many studies are concerned about total Hg rather than speciated Hg (Total Hg, Reactive Hg, Dissolved Hg, Particulate Hg, Dissolved MeHg and Particulate MeHg). Known as "the third pole", the Tibetan Plateau is a pristine and background region, and thus provides a unique and ideal place for wet Hg deposition study. In this project, precipitation samples will be continuously collected from 8 observation stations on the Tibetan Plateau, and analyzed for speciated Hg as well as further chemical or physical parameters in order to discuss the spatial-temporal characteristics of wet Hg deposition and its controlling factor. Meanwhile, the spatial-temporal pattern of wet Hg deposition will be tentatively simulated with GEOS-Chem model, and then compared with observed data to verify model perf

英文关键词： Tibetan Plateau；Atmospheric Hg deposition；GEOS-Chem model；Spatial and temporal characteristics；