Air-sea carbon cycling in mixed ice-ocean environments

由于世界海洋是地球上最大的碳汇，抵消了目前人为排放的30%左右，因此我们了解海洋碳循环的重要特征以及这些特征在大气环流模型中的合理表现尤为重要。我们对该系统的CO2源/汇动态的理解中的一个关键差距与海冰所起的作用有关。模型和极地海洋CO2通量研究所采用的传统假设是海冰作为不可渗透层存在，阻止海气交换。过去十年的研究表明，海冰是海洋碳循环的积极参与者，在海洋和大气之间交换二氧化碳，因此，海冰是极地海洋碳循环被动参与者的假设是不正确的。 尽管我们对海冰碳酸盐系统的理解有所进步，但我们仍然不知道海冰如何影响海-气CO2交换，以及海冰对区域碳预算的净影响。 我提议的研究的首要目标是了解海冰和海冰损失对北极海洋碳收支的上（大气）分支的影响。 嵌入的子目标是开发参数化的空气-冰-海洋运输的无机碳和混合冰海洋环境中的CO2的空气-海洋交换。 所提出的方法包括实地考察和冰罐实验。 实地项目将以船舶和冰营为基础，并将涉及使用涡度相关系统直接测量CO2通量，同时测量表面小气候以及海冰和水柱的CO2系统组成部分。

Because the world's oceans are the largest of the planet's carbon sinks, offsetting around 30% of present anthropogenic emissions, it is especially important that we understand important features of the marine carbon cycle and that these features are soundly represented in general circulation models. A critical gap in our understanding of the system's CO2 source/sink dynamics relates to the role played by sea ice. The traditional assumption adopted for both models and polar marine CO2 flux studies is for sea ice to exist as an impermeable layer, preventing air-sea exchange. Research in the last decade has shown sea ice to be an active participant in the marine carbon cycle, exchanging CO2 between both the ocean and atmosphere, and hence the assumption that sea ice is a passive participant in the polar marine carbon cycle is incorrect. Despite advancements in our understanding of the sea ice carbonate system, we still do not know exactly how sea ice influences air-sea CO2 exchange, and by extension, the net effect of sea ice on a region's carbon budget. The over-arching objective of my proposed research is to understand the implications of sea ice and sea ice loss on the upper (atmospheric) limb of the Arctic marine carbon budget. Imbedded are the sub-objectives to develop parameterizations for both the air-ice-ocean transport of inorganic carbon and for air-sea exchange of CO2 in mixed-ice ocean environments. Proposed methods involve a mix of field expeditions and ice tank experiments. Field projects will be both ship- and ice-camp based, and will involve the direct measurement of the CO2 flux using eddy covariance systems, in conjunction with the measurement of surface microclimate, and CO2 system components of sea ice and the water column.