Collaborative Research: Observations of the Structure and Dynamics of Mid-Shelf Fronts

提出了一个包括遥感、船载、系泊和自动车辆测量的现场计划，以获得关于大西洋中部海湾锋面结构和可变性的基本观测数据。虽然在SST中检测到了这一特征，但从动力学的角度来看，这是一个盐度锋面，将凉爽、低盐度的内陆架水与温暖的、盐度较高的外陆架水分开。该项目的目标是检验两种相互竞争的中陆架锋面的形成理论，确定中陆架锋面的垂直结构和可变性，并评估该锋面是否对跨陆架交换溶解和颗粒物质起到了屏障作用。将对卫星SST、高频雷达表面流和自主滑翔机部分的同时观测进行分析，以确定表面速度急流(如果存在)、表面热锋和地下水文结构之间的关系。拖曳起伏车辆将被用来获得多个高分辨率的水文和流速的跨锋面剖面，以阐明锋面结构在潮汐和潮下时间尺度上的变化。对短暂的镭同位素活度的测量将被用来推断跨架混合速度。在3个月的时间里对速度和水文剖面进行系泊观测将使我们能够估计跨陆架浮力通量及其差异。增进我们对陆架中锋的理解，这将有助于确定沿海海洋在碳循环中的作用的更广泛的科学推动力。研究幼鱼和幼鱼的研究人员也很感兴趣，因为这可能会影响到产卵和育苗区相隔很远的生物(如蓝鱼)的招募。计划与URI海洋项目办公室合作，让K-12教师接触到海洋方面的知识。将通过向教育工作者提供数据，与大西洋中部海洋科学教育卓越中心建立伙伴关系。描述海洋锋面的影响和产生的课程将被添加到已经张贴在COOL课堂上的现有项目中[http://www.coolclassroom.org].该项目将为本科生提供研究机会，并将包括培养一名研究生。

A field program including remotely sensed, shipboard, moored, and autonomous vehicle measurements is proposed to obtain basic observational data on the structure and variability of the front in the mid-Atlantic Bight. Although detected in SST, from a dynamical perspective this feature is a salinity front that separates cool, lower salinity inner shelf water from warm, saltier outer shelf water. The vertical structure of this front is poorly known and the mechanism of formation has not been described.The objectives of the project are to test two competing theories for the formation of the mid-shelf front, determine the vertical structure and variability of the front, and to evaluate whether the front acts as a barrier to cross-shelf exchange of dissolved and particulate materials. Concurrent observations of satellite SST, HF radar surface currents, and autonomous glider sections will be analyzed to determine the relationship between the surface velocity jet, if present, the surface thermal front, and the subsurface hydrographic structure. A towed undulating vehicle will be used to obtain multiple high-resolution cross-frontal sections of hydrography and velocity to elucidate how the frontal structure varies on tidal and subtidal time scales. Measurements of the activities of short-lived radium isotopes will be used to infer crossshelf mixing rates. Moored observations of velocity and hydrographic profiles over a 3-month period will allow estimation of the cross-shelf buoyancy flux and its divergence.Improving our understanding of mid-shelf fronts, which are ubiquitous in the coastal ocean, will contribute to the broader scientific thrust of determining the role of the coastal ocean in the carbon cycle. It is also of interest to researchers studying larval and juvenile fish, as it likely impacts recruitment of organisms with widely separated spawning and nursery areas (such as bluefish).Collaboration is planned with the URI Office of Marine Programs in their outreach efforts to give K-12 teachers exposure to sea-going oceanographic. A partnership with the Mid-Atlantic Center for Ocean Science Education Excellence will be developed by making data available to educators. Curricula describing the impact and generation of ocean fronts will be added to existing projects already posted on the COOLClassroom [http://www.coolclassroom.org]. The project will provide research opportunities for undergraduate students and will include the training of a graduate student.