Cryoreactions and Arctic marine cryospheric chemistry

快速变化的北冰洋为社会经济发展提供了前所未有的机遇；与此相关的是，在保护环境完整性、生态系统服务、粮食安全和因纽特人和其他土著人民的生活方式方面面临着前所未有的挑战。我的研究项目是在水冻结温度或低于水冻结温度的化学反应上进行基础和应用研究，被称为冷冻反应，以及它们在环境命运中的作用，以及在气候变化的北极遗留和新出现的污染物的影响。在接下来的五年里，我建议描述和参数化发生在温度、盐度、压力、pH值、氧化还原和光照条件下的化学反应，这些条件类似于北极海洋冰冻圈，包括海冰、上覆的雪和下面的海水。重点将放在过去和目前全球排放的汞、北极日益增加的海上航运活动造成的石油泄漏，以及作为重建北冰洋过去海冰变化的潜在代理的溴-汞耦合冷冻光化学。研究方法将结合曼尼托巴大学专门的冰冻圈实验室在完全受控条件下的分子水平研究和加拿大北冰洋（如哈德逊湾、巴芬湾、波弗特海）的实地研究。在这两个尺度之间架起桥梁的是温尼伯海冰环境研究设施的中尺度研究和马尼托巴省丘吉尔市新运作的丘吉尔海洋观测站。连同地球化学和全球气候汞模拟研究，拟议的研究将把对低温反应的分子水平理解用于预测北极海洋冰冻圈时空动态的过去、正在和未来的变化及其对生态系统和人类健康的影响。拟设立的研究项目将直接培养至少13名高素质人才，其中包括1名研究助理、1名博士后、3名博士、3名硕士、5名大四本科生。低温反应和冰冻圈化学是新的科学前沿，具有巨大的潜力，可以发现在冰冻温度下新的反应途径和机制的基础科学。对汞和石油泄漏的关注主要是由我与从哈德逊湾西部到北极高地的北极社区长达十年的接触所推动的。对冰冻圈化学过程的进一步了解将使我们能够改进北极生态系统从汞污染中恢复的预测，管理和应对北极水域日益增加的石油泄漏风险，并更好地预测未来的海冰变化。他们将共同支持加拿大北极及其他地区的污染控制和气候变化适应的政策制定和技术创新。

A rapidly changing Arctic Ocean is opening up unprecedented opportunities for socio-economic development; associated with these are unparalleled challenges to protect environmental integrity, ecosystem services, food security and the ways of living for Inuit and other Indigenous peoples. My research program pursues fundamental and applied studies on chemical reactions at or below water-freezing temperatures, known as cryoreactions, and their roles in environmental fate and effects of legacy and emerging contaminants in the Arctic in a changing climate. Over the next five years, I propose to characterize and parameterize chemical reactions occurring at temperature, salinity, pressure, pH, redox, and light conditions resembling those of the Arctic marine cryosphere including sea ice, the overlying snow and underlying seawater. The focus will be on mercury from past and ongoing global emissions, oil spills from increasing marine shipping activities in the Arctic, and the coupled bromine-mercury cryophotochemistry as a potential proxy to reconstruct past sea ice variability in the Arctic Ocean. The research methodology will integrate molecular-level studies at a dedicated cryospheric laboratory under fully controlled conditions at the University of Manitoba and field studies across the Canadian Arctic Ocean (e.g., Hudson Bay, Baffin Bay, Beaufort Sea). Bridging between these two scales are mesocosm-scale studies at the Sea-ice Environmental Research Facility in Winnipeg and the newly operational Churchill Marine Observatory in Churchill, Manitoba. Together with geochemical and global climate-mercury modeling studies, the proposed research will put molecular-level understanding of cryoreactions to work to project past, ongoing, and future changes in the temporally and spatially dynamic Arctic marine cryosphere and their implications for ecosystem and human health. The proposed research program will directly train at least 13 highly qualified personnel, including one research associate, one postdoctoral research fellow, three PhD students, three MSc students, and five senior undergraduate students. Cryoreactions and cryospheric chemistry are new scientific frontiers, with great potentials for fundamental scientific discoveries of new reaction pathways and mechanisms at freezing temperatures. The focus on mercury and oil spills is largely driven by my decade-long engagement with Arctic communities from western Hudson Bay to the High Arctic. The improved understanding of cryospheric chemical processes will allow us to improve the projection of Arctic ecosystem recovery from mercury pollution, to manage and respond to the increasing risk of oil spills in Arctic waters, and to better project future sea ice variability. Collectively, they will support policy-making and technological innovations for pollution control and climate change adaptation in the Canadian Arctic and beyond.