Shelf and Bottom Water Formation Near East Antarctic Polynyas and Glaciers

近东南极冰间湖和冰川的陆架和底层水层

• 批准号: 9909374
• 负责人: Richard Fairbanks
• 金额: $ 49.77万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909374&HistoricalAwards=false
• 关键词: Shelf; Bottom; Water; Formation; Near

9909374FairbanksThis study will investigate how the formation of dense water masses on the antarctic continental shelves is affected by the periodic flushing by relatively warm circumpolar deep water, and whether the intrusion of warm water cna enhance the rate of formation of dense antarctic water. The study involves the observation of water mass modification processes on the continental shelf off the Adelie Coast in East Antarctica, near a quasi-permanent area of open water in the vicinity of the Mertz and Ninnis Glacier tongues - the so-called Mertz polynya.Antarctic coastal polynyas, formed by strong offshore winds, are often referred to as major sea ice and salt "factories" because the newly formed ice is blown seaward, allowing more ice to be formed along the coast, and because the freezing process increases the salinity of the continental shelf water. The thin ice, or even open water, implies significant heat losses from the ocean to the atmosphere, which also increases the density of the shelf water. The shelf water sinks, fills any depressions in the bottom, and is gravitationally driven down the continental slope. An additional process is identified for this study and is expected to be at work in this area: the intrusion of relatively warm water onto the continental shelf, overriding the shelf water and essentially shutting down the densification processes. The study will make use of the RVIB Nathaniel B. Palmer to obtain a closely spaced array of hydrographic stations over the continental shelf and slope along the George V Coast in the austral summer. The dat obtained here will complement a similar winter study by the Australian National Antarctic Program.***

9909374费尔班克斯本研究将调查南极大陆架上稠密水团的形成如何受到相对温暖的环极深水的周期性冲刷的影响，以及温暖水的入侵是否会增加稠密南极水的形成速率。 这项研究涉及观测南极洲东部阿德利海岸外大陆架上的水团变化过程，该大陆架靠近默茨和宁尼斯冰川舌附近的准永久开放水域-所谓的默茨冰穴。南极沿海冰穴由强烈的离岸风形成，通常被称为主要的海冰和盐“工厂”，因为新形成的冰被吹向大海，使得更多的冰形成沿着海岸，因为冻结过程增加了大陆架水的盐度。 薄冰，甚至是开放的水域，意味着海洋向大气的热量损失很大，这也增加了陆架水的密度。 陆架水下沉，填满海底的任何凹陷，并在重力的作用下沿着大陆坡向下移动。 这项研究确定了另一个过程，预计将在这一领域发挥作用：相对温暖的水侵入大陆架，覆盖大陆架水，基本上停止致密化过程。 本研究将使用RVI B Nathaniel B。Palmer在南部夏季沿乔治五世海岸沿着大陆架和斜坡上获得了一组间隔很近的水文站。 这里获得的数据将补充澳大利亚国家南极计划的类似冬季研究。