Dynamics of frontal meandering and related exchange processes at the shelfbreak south of New England

陆架断裂锋在物理和生物学上都是中大西洋湾区域海洋学最显著的特征之一。与陆架断裂锋相关的过程本质上是非线性的，并在广泛的空间和时间尺度上表现出变化。受局部不稳定性影响，陆架断裂锋面射流沿陆架断裂蜿蜒流动，并与风、陆架涡流和斜坡海暖核环相互作用。陆架断裂区也有显著的沿陆架和跨陆架的热、盐和营养物质通量，这些通量受锋面蜿蜒、风和撞击暖核环的影响。尽管在该地区进行了多年的研究，但与大陆架断裂锋的蜿蜒、底边界层动力学和跨大陆架交换有关的许多科学问题仍未得到解答。本研究的主要目的是了解新英格兰南部陆架断裂锋面弯曲的特征及其潜在动力学，以及锋面弯曲和其他强迫机制对交叉锋面交换的影响。该研究将包括对历史和未来先锋阵观测数据的分析和理想化的数值模拟，以揭示新英格兰南部大振幅陆架断裂锋面蜿蜒的形成和演化；额部弯曲的诊断特点；研究锋面弯曲、风和暖核环对陆架破碎底边界层流动的影响；研究锋面蜿蜒、风和暖核环对锋面交换的影响；并检查横额交换的沿架和垂直变化。智力优势：数值模拟将与历史和即将到来的观测分析结合使用，以解决有关新英格兰大陆架断裂锋面弯曲动力学以及锋面弯曲和其他力量对交叉交换的影响的基本科学问题。更广泛的影响：更好地了解冰架断裂锋的弯曲和交叉锋交换将为研究冰架断裂处的生物生产力和污染物扩散提供物理背景。这个项目对商业渔业和海洋保育有影响。该项目的结果将传达给公众和K- 12学生，并用于未来的推广工作，提供包括视频和多媒体演示在内的非正式教育材料。

The shelf break front is one of the most salient features of the regional oceanography of the Middle Atlantic Bight, both in terms of its physics and biology. Processes associated with the shelf break front are inherently nonlinear and exhibit variations over a broad range of spatial and temporal scales. The shelf-break frontal jet, subject to local instabilities, meanders along the shelf break and interacts with winds, continental shelf eddies and slope sea warm-core rings. The shelf-break region also has significant along- and cross-shelf fluxes of heat, salt and nutrients that are subject to modification by frontal meandering, winds and impinging warm-core rings. Despite many years of study in the region, many scientific questions related to meandering of the shelf break front, bottom boundary layer dynamics, and cross-shelf exchange remain unanswered. The primary objectives of the proposed research are to understand characteristics of the shelf-break frontal meandering south of New England, its underlying dynamics, and effects of frontal meandering and other forcing mechanisms on cross-frontal exchanges. The proposed research will consist of analysis of historical and forthcoming Pioneer Array observations and idealized numerical simulations to: reveal the formation and evolution of large amplitude shelf-break frontal meandering south of New England; diagnose characteristics of the frontal meandering; investigate the effects of frontal meandering, winds and warm-core rings on flows in the shelf-break bottom boundary layer; investigate the effects of frontal meandering, winds and warm-core rings on cross-frontal exchange; and examine the along-shelf and vertical variations of the cross-frontal exchange. Intellectual merit: Numerical simulations will be used in conjunction with analysis of historical and forthcoming observations to address fundamental scientific questions concerning dynamics of frontal meandering at the New England shelf break and effects of frontal meandering and other forces on cross-frontal exchange. Broader impacts: Better understanding of meanders of the shelf break front and cross-frontal exchange will provide the physical background for studies of biological productivity and contaminant dispersal at the shelf break. This project has implications for commercial fisheries and marine conservation. Results of this project will be communicated to general public and K- 12 students, and also used for future outreach effort providing informal education materials including video and multi-media presentations.