Marine carbon cycling in the changing Arctic Ocean

北极处于气候变化的最前沿，受到人类活动造成的温室气体排放增加的不成比例的影响。最近的估计表明，在过去的二十年里，加拿大北极地区的冰块损失急剧增加，几乎是当时的三倍或两倍。这导致冰川的淡水排放量大幅增加，这就提出了对海洋环境的潜在下游影响的问题。冰川流量可以降低盐度，增加陆地物质对沿海生态系统的输入。北极沿海生态系统是有机碳埋藏的热点。为了制定有效的政策和适应战略，必须了解气候变化将如何影响北极生态系统转化和储存碳的能力。随着冰川的持续融化，沿海生态系统的地球化学环境将发生变化，这将直接影响微生物群落的组成和功能，以及碳化合物的输入和生物利用度。该项目将利用现有的实地项目，并应用最先进的分子和同位素工具来解决气候变化对北极沿海生态系统中碳转化和埋藏的影响。我们将进行实验室实验和实地测量，重点是加拿大北极群岛（CAA）冰冻海岸沿线的地点，那里是地球上除南极洲和格陵兰岛以外冰川冰量最大的地方。该项目将特别关注琼斯湾，这是一个被冰川包围的地区，也是格里斯峡湾（Ausuittuq）因纽特人村庄的所在地。此外，我们将利用与当地社区建立的伙伴关系，在奥西图克附近的一个海洋时间序列站制定基于社区的监测（CBM）计划。我们的研究结果将为地球科学家和气候建模者提供大量信息，解决北极沿海系统内的碳将通过微生物降解保持隔离或释放到大气中的程度。

The Arctic is at the forefront of climate change and being disproportionately affected by increased greenhouse gas emissions from human activities. Recent estimates show that ice mass loss in the Canadian arctic has increased dramatically over the last twenty years - almost tripling or doubling in that time. This has led to substantial increases in freshwater discharge from glaciers which raises questions about the potential downstream effects to marine environments. Glacial discharge can lower salinity and increase the input of terrestrial material to coastal ecosystems. Arctic coastal ecosystems are hotspots for the burial of organic carbon. In order to develop effective policies and adaptation strategies, it is imperative to understand how climate change will impact the ability of Arctic ecosystems to transform and store carbon. As glaciers continue to melt, coastal ecosystems will experience changes in their geochemical environment which can directly affect the composition and function of microbial communities as well as the input and bioavailability of carbon compounds. This project will leverage an existing field program and apply state-of-the-art molecular and isotopic tools to resolve the impact of climate change on the transformation and burial of carbon in coastal Arctic ecosystems. We will conduct laboratory experiments and field measurements focusing on sites along the frozen shores of the Canadian Arctic Archipelago (CAA) which contains the largest volume of glacier ice on Earth outside of Antarctica and Greenland. The project will specifically focus on Jones Sound, a region surrounded by glaciers and home to Inuit hamlet of Grise Fiord (Ausuittuq). In addition, we will leverage an established partnership with the local community to develop a community-based monitoring (CBM) program at an ocean time series station near Ausuittuq. Our results will be highly informative to earth scientists and climate modelers by addressing the extent to which carbon within Arctic coastal systems will remain sequestered or released to the atmosphere via microbial degradation.