The Low Frequency Variability of the South Atlantic Circulation

南大西洋环流的低频变化

• 批准号: 0726994
• 负责人: Ricardo Matano
• 金额: $ 49.8万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-10-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0726994&HistoricalAwards=false
• 关键词: Low; Frequency; Variability; South; Atlantic

Several recent studies have reported a slow-down of the thermohaline circulation. Although none of them are conclusive, they all consistently point to a similar conclusion: the oceanic circulation is changing. Policymakers, however, face the dilemma that although the reported changes could be the heralded response of the oceans to global warming, they could, as well, be a natural mode of ocean variability. To differentiate natural from anthropogenic changes we need increase our understanding of the factors that control the low-frequency variability of the oceanic circulation. The thermohaline circulation is a global phenomenon and to interpret its variations we need to improve our understanding of how the different basins "communicate" with each, that is, how the variability in a particular region affects the entire system. To interpret the climate-related changes occurring in the North Atlantic, for example, we need to understand the variability of its contiguous basin, the South Atlantic; not only because its heat and salt fluxes are essential for the formation of the North Atlantic deep waters, but also because it is its naturallink with all the other major oceans. In this project scientists from Oregon State University will combine the results of ocean general circulation models with remote and in-situ observation to determine the dominant patterns of low-frequency variability of the South Atlantic circulation. Broader impacts: This study is focused on those aspects of the South Atlantic circulation that are most relevant to the climate system and its broader impacts are related to it. Little is known about the low-frequency variations of the South Atlantic circulation and its interocean exchanges. This dearth of information is of serious concern to the scientific community because the South Atlantic is the only nexus between the North Atlantic and the rest of the world ocean.

最近的几项研究报告了温盐环流的减缓。虽然没有一个是结论性的，但它们都一致指向一个相似的结论：海洋环流正在发生变化。然而，决策者面临的困境是，虽然报告的变化可能是海洋对全球变暖的反应，但它们也可能是海洋变化的一种自然模式。为了区分自然变化和人为变化，我们需要进一步了解控制海洋环流低频变化的因素。温盐环流是一种全球现象，为了解释其变化，我们需要更好地理解不同盆地之间是如何“交流”的，也就是说，特定区域的变化如何影响整个系统。例如，为了解释北大西洋发生的与气候有关的变化，我们需要了解其毗连盆地南大西洋的变化;这不仅是因为南大西洋的热通量和盐通量对于北大西洋深水沃茨的形成至关重要，而且还因为南大西洋是北大西洋与所有其他主要海洋的天然联系。在这一项目中，来自俄勒冈州州立大学的科学家将联合收割机的海洋环流模型的结果与远程和现场观测相结合，以确定南大西洋环流低频变化的主要模式。更广泛的影响：这项研究的重点是南大西洋环流中与气候系统最相关的方面，以及与气候系统有关的更广泛的影响，但对南大西洋环流的低频变化及其大洋间交换知之甚少。科学界对这种信息的缺乏感到严重关切，因为南大西洋是北大西洋与世界其他海洋之间的唯一联系。