The interaction between sea ice, ocean biogeochemistry and ecosystem function

北极冰冻圈最近的许多变化非常剧烈，甚至超过了对未来变化最极端的预测。其中一些冰冻圈的变化预计会通过遥远的联系影响当地、区域甚至全球气候。然而，与冰冻圈变化相关的气候反馈极其复杂，随时间和空间的变化而变化，人们对其了解甚少。我的项目的长期目标是了解气候引起的海冰和淡水动态变化如何改变海洋北极的生物地球化学和生态功能。这将为确定极地海洋在缓冲气候活性气体排放方面的作用提供关键的见解。将特别关注确定冰藻群落在支持气候变化反馈机制方面的作用。这些独特的微生物群落在海冰的极端生物群系中茁壮成长，并有助于有机物质、营养物质和气候活性气体的形成和循环。然而，人们对冰藻生态学及其在海洋-海洋冰-大气交换中发挥的潜在重要作用知之甚少。我将探索和量化冰相关微生物群落的代谢活动。我项目的短期目标是确定冰藻群落在支持气候变化反馈机制方面的作用。为了达到这个目标，我将：1。解析海冰在冻结和融化周期中复杂的三维结构（冰、盐水、气体、生物群）；2. 量化这如何影响自养冰藻群落的光照条件和控制冰藻在有机物释放、热收支和海洋与大气之间的二氧化碳交换中的作用的净群落代谢。3. 培养博士2名，硕士2名，本科生5名。该项目的研究结果将有助于改进目前北极海冰对北极作为二氧化碳汇和辐射强迫产生源作用的影响模式，从而改进区域和全球气候模式。

Many recent changes in the Arctic cryosphere have been dramatic and have exceeded even the most extreme projections of future change. Some of these cryosphere changes are expected to affect local, regional and even global climate through distant connections. However, climate feedbacks associated with the changing cryosphere are extremely complex, vary over space and time, and are still generally poorly understood. The long-term goal of my program is to understand how climate-induced changes in sea ice and freshwater dynamics transform the biogeochemical and ecological function of the marine Arctic. This will provide critical insight for defining the role of the polar oceans in buffering emissions of climate-active gasses. Special focus will be allocated to determine the role of ice algal communities in supporting feedback mechanisms with climate change. These unique microbial communities thrive within the extreme biome of the sea ice and contribute to the formation and cycling of organic material, nutrients and climate active gasses. However, very little is known about ice algal ecology and the potentially important role that they play in ocean–sea ice–atmosphere exchange. I will explore and quantify the metabolic activity of ice-associated microbial communities. The short-term goal of my program is to determine the role of ice algal communities in supporting feedback mechanisms with climate change. To achieve this goal I will: 1. Resolve the complex 3-D structure of sea ice (ice, brine, gasses, biota) during ice freeze and thawing cycles; 2. Quantify how this affects light conditions for the autotrophic ice algal community and net community metabolism governing ice algae's role in organic matter release, thermal budget and CO2 exchange between the ocean and atmosphere. 3. Train 2 PhD, 2 MSc and 5 undergraduate students during this project. The project findings will be instrumental in improving current models of Arctic sea ice effects on the role of the Arctic as a CO2 sink and generator of radiative forcing, thereby improving regional and global climate models.