The death of Agulhas rings and the emergence of a modified Brazil Current

厄加勒斯环的死亡和改良巴西洋流的出现

• 批准号: 0928271
• 负责人: Doron Nof
• 金额: $ 47.75万
• 依托单位: Florida 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: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0928271&HistoricalAwards=false
• 关键词: death; Agulhas; rings; emergence; modified

The western South Atlantic circulation is strongly affected by rings and western boundary currents. It has been surmised that the drift of the Confluence Zone is in large part due to variations in the transports of the upstream currents approaching the confluence from the north and south (i.e., the Brazil and Malvinas currents). The project investigates the influence that Agulhas rings may have on the Brazil Current variability. Although Agulhas rings lose much of their strength and energy as they cross the entire South Atlantic, they are so large and energetic to begin with that they are still very important to the energy balance when they reach the Brazil Current and blend into it. The absorption of Agulhas rings upstream by the Brazil Current is a nonlinear process and the main goal is to determine the influence of Agulhas rings on the temporal variation of the Brazil Current using a combination of analytical models and process-oriented numerical simulations.Intellectual merit: New observations using satellite data vividly illustrate the importance of the above eddy-current interaction problem. The problem received limited attention in the past primarily because it is a very difficult nonlinear problem. Dr. Nof's previous work on the very same subject has shown that it is not a simple matter to determine whether the rings would strengthen or weaken the Brazil Current. He and collaborators have now developed analytical and numerical techniques, which should, for the first time, enable us to give the answer to the above question.Broader impacts: The study would benefit society by (i) the education of a new Ph.D., and (ii) providing a continuous series of lectures and demonstrations to unprivileged kids at the Florida Sheriffs Youth Branch in Live Oak.

南大西洋西部环流受到环和西部边界流的强烈影响。据推测，汇合带的漂移在很大程度上是由于从南北方向接近汇合处的上游流（即巴西流和马尔维纳斯流）的输运变化所致。该项目调查了阿古拉斯环可能对巴西洋流变化的影响。虽然阿古拉斯环在穿越整个南大西洋时失去了很多力量和能量，但它们一开始是如此巨大和充满活力，以至于当它们到达巴西洋流并融入其中时，它们对能量平衡仍然非常重要。巴西洋流对上游阿古拉斯环的吸收是一个非线性过程，主要目的是利用分析模式和面向过程的数值模拟相结合的方法确定阿古拉斯环对巴西洋流时间变化的影响。知识价值：利用卫星数据进行的新观测生动地说明了上述涡流相互作用问题的重要性。由于该问题是一个非常困难的非线性问题，过去人们对它的关注有限。诺夫博士之前对同一主题的研究表明，要确定这些环是会增强还是削弱巴西洋流，并不是一件简单的事情。他和合作者现在已经发展了分析和数值技术，这应该是第一次使我们能够给出上述问题的答案。更广泛的影响：这项研究将通过以下方式造福社会：(1)培养新的博士，(2)在奥夫克的佛罗里达治安官青年分部为贫困儿童提供一系列连续的讲座和示范。