Collaborative Research: What Do Global Surface Drifters Tell Us About Submesoscale Processess?

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。最近对地表环流（具有明确旋转感的漂移轨迹）的全球普查揭示了亚中尺度结构分布的一些意想不到的特征（R15 km; Griffa, Lumpkin, and Veneziani 2008）。出现了三个主要区域：a) 10&amp；#8722处普遍存在气旋带状带；20度纬度；B) 30&amp；#8722处普遍存在反气旋纬向带；40度和c)没有亚中尺度存在的区域，对应于大环的形成区域。这种分布背后的动力机制尚不完全清楚，原因之一是小环可能是不同过程的特征，如亚中尺度涡旋和亚惯性Ekman响应。本研究主要关注亚中尺度分量，并探讨了这些发现对公海亚中尺度分布的意义。要解决的问题是：世界海洋中的亚中尺度过程是否以极性和丰度的非寻常分布为特征，并受到形成它们的环境大尺度动力机制的调节？这个问题不能仅仅通过拉格朗日数据来研究，而其他全球数据集或全球数值模式没有足够的空间和时间分辨率来解决亚中尺度结构。因此，由漂流者提出的关键选定区域的非常高分辨率（高达300米）区域模型将用于研究欧拉和拉格朗日动力学。这将由区域模拟结果所显示的理想化配置下的具体过程研究加以补充。总的结果将是增加对开放海洋亚中尺度过程的性质和分布的了解。这项拟议的研究具有社会影响，因为它有助于了解上层海洋的气候和生物过程。研究结果将在UCSC和RSMAS的研究生班上公布，并将成为推广项目的一部分。为模拟ROMS模型而开发的分析算法将通过WikiROMS网页免费分发给更大的科学界。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).A recent global census of surface loopers (drifter trajectories with a definite sense of rotation) has revealed some unexpected features of the distribution of structures at scales of the submesoscale (R15 km; Griffa, Lumpkin, and Veneziani 2008). Three main regimes have emerged: a) a prevalently cyclonic zonal band at 10−20 degrees latitude; b) a prevalently anticyclonic zonal band at 30−40 degrees and c) regions devoid of submesoscale presence corresponding to areas of formation of great rings. The dynamical mechanisms behind this distribution are not completely understood yet, one of the reasons being that small loopers can be the signature of different processes, such as submesoscale eddies and subinertial Ekman response.This study focuses on the submesoscale component, and investigates the implications of the findings for submesoscale distribution in the open ocean. The question to be addressed is: Are submesoscale processes in the world ocean characterized by a nontrivial distribution in terms of polarity and abundance, modulated by the ambient large-scale dynamical regimes in which they form? This question cannot be investigated by means of Lagrangian data alone, and other global data sets or global numerical models do not have sufficient spatial and temporal resolution to solve submesoscale structures. Therefore very high resolution (up to 300 m) regional models of key selected areas suggested by the drifters will be used to investigate the Eulerian and Lagrangian dynamics. This will be complemented by specific process studies in idealized configurations indicated by the regional modeling results. The overall result will be an increased understanding of the properties and distribution of open ocean submesoscale processes.The proposed research has a societal impact because it contributes to the understanding of climate and biological processes in the upper ocean. The results will be presented in graduate classes at UCSC and RSMAS, and they will be part of outreach programs. Analysis algorithms developed for the ROMS model simulations will be freely distributed to the greater scientific community through the WikiROMS web-pages.