The Northwestern North Atlantic: a Retrospective Analysis of Observations from the CV Oleander on the Shelf and Slope

北大西洋西北部：CV Oleander 在陆架和斜坡上观测的回顾性分析

• 批准号: 1634094
• 负责人: Magdalena Andres
• 金额: $ 47.79万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1634094&HistoricalAwards=false
• 关键词: Northwestern; North; Atlantic; Retrospective; Analysis

This study examines the long-term variability in the northwestern North Atlantic over the continental shelf and slope using long-duration observations collected by a ship of opportunity and output from a regional high-resolution numerical model. This area has been highlighted as a hotspot of sea level rise and ocean warming with the trends superimposed on strong interannual to decadal variability. This study will investigate the processes driving the low-frequency variability of shelf temperature and sea level, with a focus on the physical mechanisms underlying the recent changes. The project also includes the development of observation-based coastal temperature indexes from profiles collected by the CV Oleander, a commercial vessel that operates weekly round-trip transits between New Jersey and Bermuda, and investigation of potential predictors of interannual variability of these temperature indexes relating to sea level and atmospheric pressure. The processes to be studied have important implications for both climate and commercial fisheries. Results will be presented in both climate and continental shelf workshops. The PIs will provide the data products derived from the observations to the science community via existing Oleander Program websites. The PIs will also continue public communication and outreach efforts including visits to a local 8th grade classroom, building on a long-term outreach effort with the middle school science teacher and outreach directed to commercial fishermen through the Commercial Fisheries Research Foundation in Rhode Island, which has strong links to Woods Hole Oceanographic Institution. This project will support and train a graduate student who has already published a peer-reviewed paper on this data set.The temperature sections (spanning 37 years) and velocity sections (spanning 22 years) have been collected with expendable bathythermographs (XBTs) and a shipboard acoustic Doppler current profiler (ADCP) via the CV Oleander. This data set is unique in terms of its high resolution, extended duration over multiple decades, and co-located temperature and velocity observations. Temperature data collected by the CV Oleander can resolve the interannual to decadal signals embedded in the region's annual cycle. Further, the exceptional duration of the temperature records amassed along a constant ship route, and their combination with velocity and surface salinity measurements from the ship and complementary data sets (e.g., satellite altimetry, reanalysis winds, and tide gauge data) will allow this study to characterize the variability and to explore mechanisms driving the changes such as shifts in Gulf Stream position, changes in large scale wind forcing, and changes in along-shelf advection. The study will also capitalize on existing output from a high-resolution numerical model that captures variability in the region with fidelity. This region has been identified as having a very high rate of ocean warming relative to the global mean rate. Variability in this region links open-ocean phenomena (Gulf Stream, Deep Western Boundary Current, and Atlantic Meridional Overturning Circulation, AMOC) to shelf phenomena (Middle Atlantic Bight shelf circulation, shelfbreak jet dynamics, and ecosystem dynamics).

本研究利用机会船收集的长期观测数据和区域高分辨率数值模型的输出，研究了北大西洋西北部大陆架和斜坡的长期变化。该地区被认为是海平面上升和海洋变暖的热点地区，其趋势叠加在强烈的年际到十年间的变化上。这项研究将调查驱动陆架温度和海平面低频变化的过程，重点关注近期变化背后的物理机制。该项目还包括根据 CV Oleander（一艘每周在新泽西和百慕大之间往返的商船）收集的剖面图开发基于观测的沿海温度指数，并调查这些温度指数年际变化的潜在预测因子到海平面和大气压力。要研究的过程对气候和商业渔业都有重要影响。结果将在气候和大陆架研讨会上公布。 PI 将通过现有的 Oleander 计划网站向科学界提供观察所得的数据产品。 PI 还将继续开展公共沟通和外展工作，包括参观当地八年级教室，与中学科学教师进行长期外展工作，并通过罗德岛州商业渔业研究基金会向商业渔民进行外展活动。与伍兹霍尔海洋研究所有着密切的联系。该项目将支持和培训一名已就此数据集发表同行评审论文的研究生。温度剖面（跨越 37 年）和速度剖面（跨越 22 年）已通过消耗性深海温度计 (XBT) 和通过 CV Oleander 的船载声学多普勒电流分析仪 (ADCP)。该数据集的独特之处在于其高分辨率、长达数十年的持续时间以及同一地点的温度和速度观测。 CV Oleander 收集的温度数据可以解析该地区年周期中嵌入的年际至年代际信号。此外，沿着恒定的船舶航线收集的温度记录的异常持续时间，以及它们与船舶的速度和表面盐度测量以及补充数据集（例如卫星测高、再分析风和潮汐计数据）的结合将使这项研究成为可能表征变异性并探索驱动变化的机制，例如墨西哥湾流位置的变化、大规模风力强迫的变化以及沿陆架平流的变化。该研究还将利用高分辨率数值模型的现有输出，该模型保真度地捕捉该地区的变化。与全球平均水平相比，该地区的海洋变暖速度已被确定为非常高。该区域的变化将公海现象（墨西哥湾流、深西边界流和大西洋经向翻转环流，AMOC）与陆架现象（中大西洋湾陆架环流、陆架急流动力学和生态系统动力学）联系起来。