A Numerical Study of the Patagonia Upwelling Region

巴塔哥尼亚上升流区域的数值研究

• 批准号: 0928348
• 负责人: Ricardo Matano
• 金额: $ 58.77万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928348&HistoricalAwards=false
• 关键词: Numerical; Study; Patagonia; Upwelling; Region

The Patagonia shelf is a broad submarine terrace that extends from the mouth of the La Plata River (~36S) to the tip of Tierra del Fuego (~55S). Satellite and in-situ observations indicate that this region is an active upwelling center harboring some of the largest chlorophyll blooms of the world ocean, the most distinctive of which is located at the shelfbreak. Patagonia's shelfbreak upwelling brings iron and other nutrient from the deep layers of the Southern Ocean to the photic zone, fertilizing not only the shelf waters, but also the entire subpolar portion of the South Atlantic. Satellite observations, for example, show chlorophyll plumes extending from South America to Australia. Yet, in spite of its regional and hemispheric impact, we know little about Patagonia's upwelling regime or its interaction with the deep-ocean circulation, which this project intends to address. This is a modeling study to investigate the dynamical mechanisms driving Patagonia's shelfbreak upwelling and the interactions between the shelf and the deep ocean. The basic premise is that the shelfbreak upwelling is primarily modulated by the along-shelf variations of the bottom topography and time variations of the Malvinas Current transport. The study seeks to quantify the spatial and temporal variability of the upwelling and link it to the atmospheric forcing. It is hypothesized that, although local wind might have little impact over the upwelling, large-scale wind variations, particularly those over the Pacific and Indian basins might significantly influence its variability. The study will also identify the regions of Patagonia with the largest cross-shelf exchanges and identify the dynamical mechanisms controlling these exchanges. It is anticipated that Patagonia entrains Subantarctic waters through the Le Maire Straits and the shelfbreak region between ~50S and 46S, and primarily detrains at the Subtropical Shelf Front.Broader ImpactsThis study will contribute to the development to ongoing and future biological and geochemical projects of the southwestern Atlantic region. For example, the upwelling index that will be developed by this project will help to relate observed changes in the Patagonia's ecosystems to variations in the magnitude of the shelfbreak upwelling and to large-scale modes of climate variability. The identification of cross-shelf exchanges mechanisms (and regions) will contribute to our understanding of carbon cycles and the development of future observational programs. The multi-disciplinary workshop proposed as part of this project will foster international cooperation. The project includes support for a PhD student who, throughout her/his studies, will work in close collaboration with oceanographers in Latin America. This strategy should help to foster the north-south integration of the next generation of scientists interested in shelf dynamics.Intellectual MeritAt its most basic level this project proposes to test new ideas about the dynamical mechanisms generating shelfbreak upwelling and controlling cross-shelf exchanges in regions bounded by cyclonic western boundary currents. The arguments are general enough to be applicable to other similar regions (e.g., New Zealand, Japan, the Weddell Sea, etc), thus broadening the potential impact of the intellectual work developed in this project.

巴塔哥尼亚架子是一个宽阔的潜艇露台，从拉普拉塔河（La Plata River）的河口（〜36s）延伸到蒂拉·德尔·菲格戈（Tierra del Fuego）的尖端（〜55s）。卫星和原位观察结果表明，该地区是一个活跃的上升流中心，拥有一些世界海洋中最大的叶绿素绽放，其中最独特的是位于Shelfbreak的。巴塔哥尼亚的搁置上升的上流将铁和其他养分从南大洋的深层带到光学区域，不仅施肥了架子水域，而且还施肥了南大西洋的整个亚极部分。例如，卫星观察结果表明叶绿素羽毛从南美延伸到澳大利亚。然而，尽管它具有区域性和半球影响，但我们对巴塔哥尼亚的上升流动政权或与深海洋循环的互动知之甚少，该项目打算解决。这是一项建模研究，旨在研究推动巴塔哥尼亚的地板上升的上升以及货架与深海之间的相互作用的动力学机制。基本的前提是，地理上升的上升主要是由底部地形和Malvinas电流传输的时间变化的沿架子变化所调节的。该研究旨在量化上升流的空间和时间变化，并将其与大气强迫链接起来。假设，尽管当地风可能对上升的大规模风变化影响很小，尤其是太平洋和印度盆地的风质可能会极大地影响其可变性。该研究还将以最大的交叉交换来确定巴塔哥尼亚的区域，并确定控制这些交易所的动力学机制。预计巴塔哥尼亚通过Le Maire Strait和左右的货架破裂区域侵入了〜50至46S之间的货架破裂区域，主要是在亚热带货架前部的损害。这项研究将有助于这项研究对正在进行的和未来的生物学和未来的生物学和地球化学项目的发展。例如，该项目将开发的上升指数将有助于将观察到的巴塔哥尼亚生态系统的变化与固定式上升上升的幅度以及气候变化的大规模模式相关联。跨货架交换机制（和地区）的识别将有助于我们对碳周期的理解和未来观察计划的发展。作为该项目的一部分提议的多学科研讨会将促进国际合作。该项目包括对一名博士生的支持，该博士在整个学习过程中将与拉丁美洲的海洋学家密切合作。该策略应有助于促进对货架动力学感兴趣的下一代科学家的南北整合。智能绩效其最基本的水平本项目提出的最基本的层面旨在测试有关在旋风西部边界界限的地区的动力学机制上的新想法。这些论点足以适用于其他类似地区（例如新西兰，日本，韦德尔海等），从而扩大了该项目中智力工作的潜在影响。