Collaborative Research: Using opportunistic radon measurements to estimate the gas transfer velocity in partial sea ice cover

合作研究：利用机会性氡气测量来估计部分海冰覆盖中的气体传输速度

• 批准号: 1203854
• 负责人: William Smethie
• 金额: $ 3.92万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-11-01 至 2014-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203854&HistoricalAwards=false
• 关键词: Collaborative; Research; Using; opportunistic; radon

This project will investigate the use of naturally-occurring radon as a tracer for gas exchange in seasonally ice-covered waters in the Arctic Ocean, using ships of opportunity for sampling. At its maximum extent, sea ice covers nearly 10% of the ocean surface, which creates an important control on the exchange of heat and biogenic gases (CO2, O2, DMS) between the ocean and atmosphere. In the Arctic, the summer minimum in sea ice cover is rapidly decreasing and this implies a greater oscillation between the minimum and maximum sea ice extents. The effect of this increased oscillation on the net air-sea exchange of gases is not certain because sea ice is interconnected with upper ocean physics and biology. What appears certain, is that the Arctic surface ocean will experience greater variability in ice cover and this increase in variability emphasizes the need for a predictive map of air-sea gas exchange versus the forcing conditions in the sea ice zone. Sea surface convection during freezing, stratification by meltwater, and the presence of interspersed ice floes may exert important controls on the gas transfer velocity and flux of biogenic gases. A well-constrained determination of the flux of CO2 in sea ice, and in turn a well-constrained budget of polar ocean carbon, will require more detailed knowledge of gas transfer velocity in the presence of sea ice. This study proposes to make an exploratory map of the scaling relationship between the gas transfer velocity and the forcing conditions in the seasonal sea ice zone, by combining estimates of the gas transfer velocity from radon measurements with forcing conditions (such as wind and upper ocean turbulence) from Arctic Observing Network measurements and from model results. In addition to its impact on understanding carbon cycling, the project will support an early career investigator, and a graduate student.

该项目将利用机会船进行取样，调查在北冰洋季节性冰封的沃茨中使用天然氡作为气体交换示踪剂的情况。在最大程度上，海冰覆盖了近10%的海洋表面，这对海洋和大气之间的热量和生物气体（CO2，O2，DMS）交换产生了重要的控制。在北极，夏季海冰覆盖的最小值正在迅速减少，这意味着最小和最大海冰范围之间的波动更大。由于海冰与上层海洋物理学和生物学相互关联，这种振荡的增加对海-气气体净交换的影响尚不确定。似乎可以肯定的是，北极表层海洋将经历更大的冰盖变化，这种变化的增加强调了需要一个预测图的气-海气体交换与海冰区的强迫条件。冻结期间的海面对流，融水分层，以及散布的浮冰的存在下，可能会产生重要的控制气体传输速度和生物气体通量。一个很好的约束确定海冰中的CO2通量，并反过来一个很好的约束预算的极地海洋碳，将需要更详细的知识的气体传输速度在海冰的存在。本研究提出了一个探索性的地图之间的比例关系的气体传输速度和强迫条件的季节性海冰区，通过结合氡测量与强迫条件（如风和上层海洋湍流）从北极观测网络测量和模型结果的气体传输速度的估计。除了对理解碳循环的影响外，该项目还将支持一名早期职业调查员和一名研究生。