CAREER: Physical Modulation of Dissolved Oxygen in Chesapeake Bay

职业：切萨皮克湾溶解氧的物理调节

• 批准号: 0954690
• 负责人: Malcolm Scully
• 金额: $ 74.37万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0954690&HistoricalAwards=false
• 关键词: CAREER; Physical; Modulation; Dissolved; Oxygen

Physical processes play a dominant role in controlling the inter-annual variability of summertime hypoxia in Chesapeake Bay. The classical model for the development of hypoxia in the Bay assumes a simple one-dimensional balance in which biological oxygen demand exceeds the vertical supply of dissolved oxygen through the pycnocline by turbulent mixing. The PI's recent work suggests a new model for the modulation of hypoxia in which dissolved oxygen is supplied to the sub-pycnocline waters not through direct vertical mixing, but rather through the interactions of lateral circulation and mixing near the boundaries. It is hypothesized that wind-driven lateral circulation is the dominant mechanism that supplies dissolved oxygen to regions susceptible to hypoxia, and that the effectiveness of this mechanism is sensitive to both wind direction as well as estuarine bathymetry. This is supported by both numerical simulations and historical data, but comprehensive field measurements are required to adequately test this hypothesis. The overall research objective of this project is to develop a comprehensive understanding of how physical forcing, including winds, tides and density stratification, modulates dissolved oxygen in Chesapeake Bay. This objective will be achieved through a comprehensive examination of the interactions between circulation, density stratification and estuarine bathymetry and how these interactions ultimately govern when and where the turbulent scalar (salinity, temperature, and oxygen) flux occurs. The public awareness and local importance of hypoxia in Chesapeake Bay make it an ideal socio-scientific issue for a comprehensive context-based education plan for students and the general public in the greater Hampton Roads area. The educational activities in this project will promote an interdisciplinary examination of hypoxia in Chesapeake Bay that highlights the interactions between biological and physical processes and stresses the role of science in shaping public policy.Intellectual Merit: Understanding how circulation interacts with density stratification to control when and where turbulent scalar flux occurs is a fundamental problem in coastal and estuarine oceanography. It significantly impacts a wide range of physical and biogeochemical processes and exerts a first order control on hypoxia. Hypoxia is one of the most pressing water quality issues facing coastal and estuarine waters, yet there are few if any detailed studies that resolve the turbulent mixing processes that modulate dissolved oxygen. The measurements collected here will represent the most comprehensive examination of turbulent mixing in Chesapeake Bay, including unprecedented measurements of the direct turbulent flux of oxygen.Broader Impacts: The scientific goals of this study are of fundamental importance to assessing efforts to restore water quality in Chesapeake Bay. The results from this research will help regulatory agencies and policymakers better design and assess restoration efforts in this economically and ecologically important estuary. The educational activities of this proposal are designed to promote scientific literacy about the issue of hypoxia by targeting both the general public and students across a wide range of educational levels. The development of the Summer Hypoxia/Anoxia Research Program (SHARP) will provide unique research opportunities for undergraduate students, specifically targeting underrepresented minorities through a partnership with Hampton University. The integration of hypoxia into the Chesapeake Interactive Modeling Program (CHIMP) will provide a powerful tool for educating the public about one of the most important water quality issues in Chesapeake Bay. This new tool will be made available to the extensive group of educators already using the original version of CHIMP, and it will be used to educate middle school students involved in the Mentoring Young Scientist Program and the general public through a display at the Virginia Aquarium.

物理过程在控制切萨皮克湾夏季缺氧的年际变化中起主导作用。在海湾缺氧的发展的经典模型假设一个简单的一维平衡，其中生物的氧需求超过溶解氧的垂直供应通过密度跃层湍流混合。PI的最近的工作提出了一个新的模式，为缺氧的调制中，溶解氧供应到次密度跃层沃茨不是通过直接的垂直混合，而是通过横向循环和混合的边界附近的相互作用。据推测，风驱动的横向环流是主要的机制，供应溶解氧的地区容易缺氧，这种机制的有效性是敏感的风向以及河口水深。数值模拟和历史数据都支持这一假设，但需要全面的实地测量来充分检验这一假设。该项目的总体研究目标是全面了解物理强迫，包括风，潮汐和密度分层，调制溶解氧在切萨皮克湾。这一目标将通过全面检查流通，密度分层和河口测深之间的相互作用，以及这些相互作用最终如何管理何时何地湍流标量（盐度，温度和氧气）通量发生。公众意识和缺氧在切萨皮克湾当地的重要性，使其成为一个理想的社会科学问题，为学生和广大公众在更大的汉普顿道路地区的全面的基于上下文的教育计划。该项目的教育活动将促进对切萨皮克湾缺氧的跨学科研究，突出生物和物理过程之间的相互作用，并强调科学在塑造公共policy.Intellectual优点：了解环流如何与密度分层相互作用，以控制湍流标量通量发生的时间和地点是沿海和河口海洋学的一个基本问题。它显著影响广泛的物理和地球化学过程，并对缺氧发挥一级控制作用。低氧是沿海和河口沃茨面临的最紧迫的水质问题之一，但很少有详细的研究，解决湍流混合过程，调节溶解氧。这里收集的测量将代表最全面的检查湍流混合在切萨皮克湾，包括前所未有的测量直接湍流通量的oxygen.Broader影响：这项研究的科学目标是根本的重要性，以评估努力恢复水质在切萨皮克湾。这项研究的结果将有助于监管机构和政策制定者更好地设计和评估这一经济和生态重要河口的恢复工作。该提案的教育活动旨在通过针对广大公众和各种教育水平的学生，促进对缺氧问题的科学认识。夏季缺氧/缺氧研究计划（SHARP）的发展将为本科生提供独特的研究机会，通过与汉普顿大学的合作，专门针对代表性不足的少数民族。缺氧的集成到切萨皮克交互式建模程序（CHIMP）将提供一个强大的工具，教育公众对切萨皮克湾最重要的水质问题之一。这一新工具将提供给已经使用CHIMP原始版本的广大教育工作者，并将通过在弗吉尼亚水族馆的展示来教育参与指导青年科学家计划的中学生和公众。