Land-ocean-climate interactions in high northern latitudes

研究项目涉及地质档案中记录的北半球高纬度地区晚新生代到近代的气候变化。它解决了关于陆地-海洋-气候相互作用的三个互补问题。一个是亚北极太平洋、北极和北大西洋之间的大规模交换，这对淡水收支、盐度、水团分层、海冰和通过海洋环流的热量再分配发挥着重要作用。第二部分侧重于陆外环境，即在陆地和海洋之间的过渡阶段，陆地淡水排放影响水文条件。第三是季节性，这是气候的一个重要组成部分，也取决于海洋环境中水团的盐度和分层。***长期目标是了解和评估淡水在高纬度气候系统中从半球到区域尺度的作用，而短期目标则以更具体的时间和空间焦点来确定。在半球尺度上，它们包括：(1)重建北极西部（楚科奇海、白令海）的海洋环境，在那里，来自北太平洋的淡水和营养物输入对海冰和生产力起决定性作用；(2)阐明北极海冰变率模式与与亚北极大西洋和太平洋的交换之间的关系；(3)评价通过弗拉姆海峡和加拿大北极群岛的北冰洋外流对北大西洋北部海洋学的相对影响。在陆表环境的区域尺度上，它们包括(4)记录格陵兰岛边缘海洋和大陆冰稳定或融化之间的相互作用，以及(5)重建加拿大北部和东部边缘的气候和水文变化，特别是育空地区、哈德逊湾、拉布拉多陆架和圣劳伦斯湾的海岸。该研究项目主要依赖于国际合作框架内收集的海洋沉积物岩心。它建立在过去几十年开发的方法之上，但仍在发展中。他们结合微古生物学、地球化学和同位素指标，同时重建气候、海面和深海条件的互补参数。***作为研究计划的一部分进行的项目涉及研究生的参与，并在将代理古气候和古生态数据采集/汇编与气候模拟工作相结合的国际倡议框架内进行协调。除了在千禧年到持续的“全球变化”尺度上发展陆地-海洋-气候相互作用的基础知识之外，研究计划的成果还包括开发环境问题评估工具。*****

The research program deals with late Cenozoic to recent climate changes at high latitudes of the Northern Hemisphere, as recorded in geological archives. It addresses three complementary questions about land-ocean-climate interactions. One concerns the large-scale exchanges between the subarctic Pacific, Arctic and North Atlantic oceans that exert an important role on the freshwater budget, thus salinity, water mass stratification, sea ice, and heat redistribution through ocean circulation. The second focuses on epicontinental environments, at the transition between land and ocean, where terrestrial freshwater discharge impacts hydrographic conditions. The third deals with seasonality, which is a critical component of climate that also depends upon salinity and stratification of water masses in marine environments. ***The long-term objective is the understanding and assessment of the role of freshwater in the climate system at high latitudes, from hemispheric to regional scales, while short-term objectives are defined with more specific temporal and spatial foci. At hemispheric scale, they include (1) the reconstruction of marine environments in the western Arctic (Chukchi, Bering seas) where freshwater and nutrient inputs from the North Pacific are determinant on sea ice and productivity, (2) the elucidation of the relationships between the modes of Arctic sea ice variability vs the exchanges with the subarctic Atlantic and Pacific seas, and (3) the evaluation of the relative impacts of Arctic Ocean outflows through Fram Strait vs the Canadian Arctic Archipelago, on the northern North Atlantic oceanography. At the regional scale of epicontinental settings, they include (4) the documenting of interactions between ocean and continental ice stability or melting along the Greenland margins, and (5) the reconstruction of climate and hydrography variabilities along the northern and eastern margins of Canada, in particular the coasts of Yukon, Hudson Bay, Labrador shelf and the Gulf of St. Lawrence. ***The research program mostly relies on access to marine sediment cores collected within the framework of international collaborations. It is built from methodologies developed over the last decades, but still in progress. They combine micropaleontological, geochemical and isotopic proxies to simultaneously reconstruct complementary parameters of climate, sea surface and deep marine conditions. ***The projects conducted as part of the research program involve participation of graduate students and are coordinated within the framework of international initiatives combining proxy paleoclimate and paleoecological data acquisition/compilation with climate modelling efforts. Beyond the development of fundamental knowledge about land-ocean-climate interactions at millennial to on-going "global changes" scales, the outcomes of the research program also include the development of tools for environmental issue assessments.*****