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在内的现场项目，以获取大西洋中部湾锋面结构和变异性的基本观测数据。虽然在海表温度中发现了这一特征，但从动力学角度来看，这一特征是一个盐度锋，它将低温、低盐度的大陆架内部水与温暖、高盐度的大陆架外部水分开。该锋面的垂直构造鲜为人知，其形成机制也未被描述。该项目的目标是测试两种相互竞争的关于中大陆架锋面形成的理论，确定锋面的垂直结构和可变性，并评估锋面是否作为溶解和颗粒物质跨大陆架交换的障碍。将分析卫星海温、高频雷达地表流和自主滑翔机剖面的同步观测，以确定地表速度射流（如果存在）、地表热锋和地下水文结构之间的关系。将使用拖曳起伏车辆获取多个高分辨率的水文和速度横断面，以阐明锋面结构在潮汐和潮下时间尺度上的变化。对短寿命镭同位素活性的测量将用于推断跨大陆架混合速率。对3个月期间的速度和水文剖面进行系泊观测，可以估计跨大陆架浮力通量及其散度。提高我们对沿海海洋中无处不在的中大陆架锋的理解，将有助于确定沿海海洋在碳循环中的作用这一更广泛的科学推力。这也是研究幼鱼和幼鱼的研究人员感兴趣的地方，因为它可能会影响产卵区和繁殖区相隔很远的生物（如蓝鱼）的招募。计划与URI海洋项目办公室合作，开展外联工作，使K-12教师接触航海海洋学。通过向教育工作者提供数据，将与中大西洋海洋科学教育卓越中心建立伙伴关系。描述海洋锋面影响和产生的课程将被添加到COOLClassroom [http://www.coolclassroom.org]]上已经发布的现有项目中。该项目将为本科生提供研究机会，并将包括对研究生的培训。

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.