ETBC: Global 3-D Modeling of Atmospheric Mercury and its Coupling to the Ocean and Land: Impacts of Past and Future Anthropogenic Emissions

该项目将增进对全球生物地球化学汞循环及其与海洋甲基汞的联系的了解，甲基汞通过食物链生物积累，并造成人类健康风险。它将使用由同化气象数据驱动的全球三维模式(GEOS-Chem)，并将包括汞形态的机械表示以及大气与陆地和海洋水库之间的转移。该模型将改进现有的GEOS-Chem版本，最主要的是纳入了一个详细的基于过程的陆地模型。尽管许多过程仍不确定，但这项工作将首先开发一种能力，以模拟陆地无机汞浓度反映的人为汞排放变化的速度。陆地-大气-海洋耦合模拟框架将使用来自大气(船舶、飞机、陆地站点)、海洋(大气-海洋交换、汞形态、与环境变量的相关性)和土壤的大量观测汞数据进行评估和约束。这项研究将为未来的工作提供一个平台，以审查(1)气候变化对全球汞循环的潜在重大影响，(2)全球汞循环与甲基汞循环之间的联系，甲基汞是积累在食物网中的可生物利用物种。这将为制定旨在通过控制人为排放降低环境汞水平的国家和国际政策提供独特的资源。多相三维建模框架将应用于其他污染物的未来建模，如持久性有机污染物。该项目将培训一名跨学科环境建模的研究生。

This project will improve understanding of the global biogeochemical mercury cycle and its link to oceanic methylmercury, which bioaccumulates through the food chain and causes human health risks. It will use a global three-dimensional model (GEOS-Chem) driven by assimilated meteorological data and will include mechanistic representations of mercury speciation and transfer between the atmosphere and terrestrial and oceanic reservoirs. The model will improve on the existing version of GEOS-Chem, most notably through the incorporation of a detailed process-based terrestrial model. Although many processes are still uncertain, the work will develop a first capability to model how rapidly changes in anthropogenic mercury emissions are reflected by terrestrial inorganic mercury concentrations. The coupled land-atmosphere-ocean modeling framework will be evaluated and constrained using a large body of observational mercury data from the atmosphere (ships, aircraft, land sites), oceans (air-sea exchange, mercury speciation, correlations with environmental variables), and soils.This research will provide a platform for future work examining (1) the potentially large impacts of climate change on the global mercury cycle, (2) the link between the global cycle of mercury and that of methylmercury, which is the bioavailable species that accumulates in food-webs. This will lead to a unique resource for the development of national and international policies targeted at reducing environmental mercury levels through control of anthropogenic emissions. The multiphase, three-dimensional modeling framework will have application to future modeling of other contaminants such as persistent organic pollutants. The project will train a graduate student in interdisciplinary environmental modeling.