Collaborative Research: Modeling Thermobaric Effects in Antarctic Deep Ocean Convection

合作研究：模拟南极深海对流的温压效应

• 批准号: 0125406
• 负责人: Miles McPhee
• 金额: --
• 依托单位: McPhee Research Company
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125406&HistoricalAwards=false
• 关键词: Collaborative; Research; Modeling; Thermobaric; Effects

This collaborative project is a modeling study of thermobaric instability in the ocean, and its effect on deep convection in the Southern Ocean. Thermobaric instability refers to the fact that the compressibility of sea water is a non-linear function of pressure, so that a colder and fresher layer overlying a warmer and a saltier layer may be statically stable, but become unstable if it is disturbed. That this is theoretically possible has been known for a long time, but only recently has it been considered as an effect that could actually occur in the Southern Ocean, specifically as the potential explanation of the episodic occurrence of polynyas (sizable areas of open water within the sea-ice pack) in the Weddell Sea. This evaluation of the impact of thermobaricity on deep ocean convection will be based on a numerical Large Eddy Simulation (LES) model capable of simulating directly the convection plumes and large scale oceanic flow features that would be expected with intense thermobaric overturn. Based on preliminary results of an LES model initialized and forced by conditions observed during previous oceanographic cruises to the Weddell Sea, this proposed work will combine a carefully structured series of model runs with observations to identify critical overturning processes.

该合作项目是对海洋温压不稳定性及其对南大洋深对流影响的建模研究。温压不稳定性是指海水的可压缩性是压力的非线性函数，因此覆盖在较暖和较咸层上的较冷和较新鲜层可能是静态稳定的，但如果受到干扰则变得不稳定。这在理论上是可能的已经知道了很长一段时间，但直到最近才被认为是一种可能在南大洋实际发生的效应，特别是作为威德尔海偶尔出现冰穴（海冰包内相当大的开放水域）的潜在解释。这种评估的影响，温压对深海对流的数值大涡模拟（LES）模型，能够直接模拟对流羽流和大规模的海洋流动功能，预计将与激烈的温压翻转的基础上。根据LES模型初始化的初步结果，并在以前的海洋巡航威德尔海观察到的条件下被迫，这项拟议的工作将结合联合收割机一个精心设计的一系列模型运行与观察，以确定关键的倾覆过程。