SGER: An Exploratory Full-Depth Section of Mixing Observations Across the Arctic Ocean

SGER：北冰洋混合观测的探索性全深度部分

• 批准号: 0527874
• 负责人: Peter Winsor
• 金额: $ 6.73万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0527874&HistoricalAwards=false
• 关键词: SGER; Exploratory; Full; Depth; Section

Funds are provided to conduct an exploratory investigation of diapycnal mixing across the entire Arctic basin from surface to full ocean depth using an innovative instrument capable of measuring microscale temperature, conductivity and velocity shear under challenging ice-covered conditions during the upcoming pan-arctic Beringia 2005 expedition. The microstructure measurements will be analyzed together with information from lowered acoustic Doppler current profiler and a full hydrographic-biogeochemical program. The dissipation rates of thermal variance and turbulent kinetic energy will be measured and used to estimate the vertical diffusivity across the whole basin. The proposed measurements are highly exploratory. Furthermore, microstructure instruments and their probes are very sensitive, adding to the uncertainty and high risk of such measurements in ice-covered regions. If successful, these observations may enable a significant leap forward in understanding of mixing in the Arctic Ocean and its influence on lateral and vertical fluxes of heat, salt and momentum. A key issue for understanding and predicting heat and freshwater uptake, storage and transport by the ocean is the rate of mixing across density surfaces in the ocean's interior. Such mixing is a prerequisite for the renewal of deep waters and is essential for upper ocean heat transfer and storage. Understanding this critical process has become more urgent of late, as it is now realized that mixing processes have very complex distributions, quite different from the uniform mixing rate assumed in models. One particularly important issue is understanding those mixing processes that control the vertical flux of heat, in the Arctic Ocean, from warm subsurface waters to the sea surface where the heat can contribute to the loss of sea ice, and how these might vary due to global change.

在即将到来的2005年泛北极白令陆桥考察期间，将使用一种能够在具有挑战性的冰覆盖条件下测量微尺度温度、电导率和速度切变的创新仪器，对整个北极盆地从表面到整个海洋深度的河床混合进行探索性调查。微观结构测量将与来自低声多普勒电流剖面仪和完整的水文生物地球化学程序的信息一起进行分析。将测量热方差和湍流动能的耗散率，并用于估计整个盆地的垂直扩散率。提出的测量方法是高度探索性的。此外，微结构仪器及其探头非常敏感，增加了在冰雪覆盖地区进行此类测量的不确定性和高风险。如果成功，这些观测可能使人们在了解北冰洋的混合及其对热量、盐和动量的横向和垂直通量的影响方面取得重大飞跃。理解和预测海洋对热量和淡水的吸收、储存和运输的一个关键问题是海洋内部密度表面的混合速率。这种混合是深水更新的先决条件，也是上层海洋热传递和储存的必要条件。理解这一关键过程最近变得更加紧迫，因为现在认识到混合过程具有非常复杂的分布，与模型中假设的均匀混合速率大不相同。一个特别重要的问题是了解那些控制北冰洋从温暖的地下水域到海面的垂直热量通量的混合过程，在海面上热量会导致海冰的损失，以及这些过程如何因全球变化而变化。