Interannual Variability of Winter-Spring Temperature in the Middle Atlantic Bight: Linkages to Large-Scale Atmospheric and Oceanic Changes

大西洋中部湾冬春季气温的年际变化：与大规模大气和海洋变化的联系

• 批准号: 1435602
• 负责人: Ke Chen
• 金额: $ 76.8万
• 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: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435602&HistoricalAwards=false
• 关键词: Interannual; Variability; Winter; Spring; Temperature

The coastal ocean off the northeastern U.S. encompassing the Gulf of Maine and the Middle Atlantic Bight is a dynamic and highly productive system supporting economically important commercial fisheries. The ocean temperature in this region experienced an extreme warming event in 2012, which greatly impacted the coastal ecosystem and commercial fisheries. Therefore, understanding year-to-year variability of ocean temperature in this region, especially extreme change such as the 2012 warming, would provide the scientific basis necessary for ecosystem management and thus has important economic impacts for the commercial fishing industry. This project investigates the roles of large-scale atmospheric and oceanic processes in the interannual variability of winter-spring temperatures in the Middle Atlantic Bight, with a focus on the extreme warm and cold years. The investigators have been discussing this research with several scientists in the National Marine Fisheries Service and plan to share the results with them. The investigators will also be in close contact with the Commercial Fisheries Research Foundation in Rhode Island to communicate the results to the commercial fishing industry in the Northeast and participate in workshops dealing with management implications of the recent extreme interannual variability in the Northeast. Finally, the investigators have been, and will continue, presenting their work to the general public. The overall objective of this research is to better understand the mechanistic links between the large-scale atmospheric/oceanic processes and the interannual temperature anomalies on the Northeast U.S. Shelf, with an ultimate goal of identifying useful predictors of extreme temperature events. Recent studies indicate that Arctic warming increases the north-south amplitude of the polar jet stream and reduces its wind speed, resulting in slower-moving weather systems in mid-latitude regions and a higher probability of extreme events. A recent case study identified a direct link between the atmospheric jet stream variability and ocean temperature anomalies on the shelf in the Middle Atlantic Bight during the unusually warm winter of 2011-2012. This research will extend this case study from one winter to a longer period with multiple extreme warm/cold winter-springs to address the following scientific questions. What is the response of the coastal ocean in the northeastern U.S. to such extreme year-to-year variability of the climate system? To what extent is the interannual variability of temperature in the Middle Atlantic Bight due to the large-scale atmospheric forcing, e.g., jet stream variability? What are the relative contributions from oceanic processes versus atmospheric processes? To better understand the relative importance of the atmospheric and oceanic processes, a detailed local ocean heat budget analysis will be carried out based on both the observations and numerical simulations. The investigators will then explore the links between the interannual variability of each heat budget term associated with the temperature anomalies over the continental shelf and the large-scale atmospheric/ocean circulation. The analysis will focus on the winter-spring period, when inter-annual anomalies are the largest. This is also the seasonal time frame when the extreme warm anomaly in 2012 and the record-low temperatures in early 2014 occurred.

美国东北部的沿海海洋涵盖了缅因州和中大西洋中部的海湾，是一种充满活力且高产的系统，支持经济上重要的商业渔业。该地区的海洋温度在2012年发生了极端的变暖事件，这极大地影响了沿海生态系统和商业渔业。因此，了解该地区海洋温度的年度变化，尤其是2012年变暖等极端变化，将为生态系统管理提供必要的科学基础，从而对商业捕鱼行业产生重要的经济影响。该项目调查了大型大气和海洋过程在中大西洋湾冬季温度的年际变化中的作用，重点是极端温暖和寒冷的岁月。 研究人员一直在与国家海洋渔业服务中的几位科学家讨论这项研究，并计划与他们分享结果。调查人员还将与罗德岛州的商业渔业研究基金会保持密切联系，以将结果传达给东北的商业捕鱼业，并参加有关东北最近极端年度际变化的管理意义的研讨会。最后，调查人员已经并且将继续向公众展示其工作。这项研究的总体目的是更好地了解大气/海洋过程与美国东北货架上的年度温度异常之间的机械联系，其最终目标是确定极端温度事件的有用预测指标。最近的研究表明，北极变暖增加了极性喷射流的南北幅度并降低了风速，从而导致中纬度地区移动较慢，并且极端事件的可能性更高。最近的一项案例研究确定了2011 - 2012年异常温暖的冬季，大气流的变异性与海洋温度异常之间的直接联系。这项研究将把这个案例研究从一个冬季扩展到更长的时期，并有多个极端温暖/寒冷的冬季春季，以解决以下科学问题。美国东北部沿海海洋对气候系统的极端变化的反应是什么？由于大规模的大气强迫，例如喷射流变化，温度在多大程度上是在大西洋中部的临时变化？海洋过程与大气过程的相对贡献是什么？为了更好地理解大气和海洋过程的相对重要性，将根据观测值和数值模拟进行详细的当地海洋热预算分析。然后，研究人员将探索与大陆架上的温度异常相关的每个热预算项的年际变化与大规模大气/海洋循环之间的联系。分析将集中在冬季春季时期，当时年度异常是最大的。这也是季节性的时间框架，2012年极端温暖的异常和2014年初的创纪录 - 低温。