Sea-ice and polynya productivity in relation to climate-induced environmental changes along the Baffin and Labrador Currents during the Holocene

这项研究计划的目的是提供关于位于拉布拉多海岸沿着和巴芬湾的主要经常性冰穴（即海冰包围的开放水域）的海冰、初级生产和水文参数长期演变的详细定性和定量资料。将对全新世中期至晚期（0-8000年）的年代确定的海洋沉积物岩心进行一系列微体化石和地球化学分析，在此期间，气候在较冷和较暖之间发生了几次转变。特别是，该计划预计由两名硕士生和两名博士生对硅藻和甲藻孢囊组合和地球化学示踪剂进行广泛分析，并辅以我自己的底层硅藻分析。这项工作将与加拿大地质调查局、丹麦和格陵兰地质调查局以及魁北克大学的同事密切合作进行。海洋初级生产者-蓝细菌、硅藻和甲藻等海洋食物网基础上的光合生物-在生态系统的生物化学和功能方面发挥着至关重要的作用。它们的生态受海洋的物理和化学特性（如海面温度和盐度、海冰覆盖、海洋环流等）的支配，这使得初级生产者对气候变化高度敏感，并成为气候变化的指标。为了对当前和未来北极变暖对巴芬/拉布拉多沿海沃茨及其经常性冰穴的生产能力的程度和后果作出可靠的预测，需要全面了解该系统对气候波动的反应。这种理解可以通过研究过去对气候变化的可比系统反应来获得。拟议的计划将有助于了解冰穴对北极生产力预算的贡献及其作为碳汇的作用。这些研究活动将有助于培养沿着古环境研究不同阶段的高素质人才。将产生的数据将提高我们的能力，以衡量目前和未来的气候变化对生态系统服务的影响，这些polynya历史上一直保持，并将帮助当地北方社区预测和准备这些变化的潜在经济和社会后果。最后，拟议的项目符合正在进行的努力的更大框架，以更好地了解气候系统，并验证海冰和初级生产构成关键组成部分的区域气候模型。

The objective of this research program is to provide detailed qualitative and quantitative information on the long-term evolution of sea ice, primary production and hydrographic parameters in key recurrent polynyas (i.e. areas of open-water surrounded by sea-ice) located along the Labrador coast and in Baffin Bay. A series of microfossil and geochemical analyses will be performed on well-dated marine sediment cores spanning the middle to late Holocene (0-8000 years), during which several transitions between colder and warmer climate intervals have occurred. In particular, the program foresees extensive analysis of diatom and dinoflagellate cyst assemblages and geochemical tracers by two MSc students and two PhD students, complemented by my own downcore diatom analysis. This will be done in close collaboration with colleagues from the Geological Survey of Canada, the Geological Survey of Denmark and Greenland, and Université du Québec.******Marine primary producers - photosynthetic organisms at the basis of marine food webs such as cyanobacteria, diatoms and dinoflagellates - play a crucial role in the biochemistry and functioning of ecosystems. Their ecology is governed by the ocean's physical and chemical properties (e.g. sea-surface temperature and salinity, sea ice cover, ocean circulation, etc.), making primary producers highly sensitive to, and indicative of, climatic changes. In order to make reliable predictions about the magnitude and consequences of current and future Arctic warming on the productive capacity of the Baffin/Labrador coastal waters and their recurrent polynyas, a complete understanding of the response of the system to climate fluctuations is required. Such an understanding can be obtained through the study of comparable system responses to climatic changes in the past.******The proposed program will help to understand the contribution of polynyas to the Arctic productivity budget and their role as carbon sinks. The research activities will contribute to the training of highly-qualified-personnel along different steps of paleo-environmental studies. The data that will be produced will increase our capacity to gauge the impact of present and future climate changes on the ecosystem services that these polynyas have historically maintained and will help local northern communities to anticipate and prepare for the potential economic and social consequences of these changes. Finally, the proposed project fits within the larger framework of ongoing efforts to better understand the climate system, and validate regional climate models in which sea ice and primary production constitute key components.