Collaborative Research: Cross-shelf Transport and Alongshelf Exchange Processes in Regions of Multiple Mesoscale Fronts

Old Dominion University Research Foundation, Norfolk VA

Investigators

Abstract

A field program will be conducted to examine the circulation and density fields associated with the Hatteras Front and its proximate fronts near Cape Hatteras. The primary observational strategy will be to deploy two research vessels equipped with ADCP, undulating-CTD sensors, and surface mapping CT sensors, to acquire repeated high resolution vertical sections and horizontal surface fields of velocity and density across the fronts. In addition, a relatively simple set of measurements will render in situ estimates of vertical eddy diffusion coefficients in and near the fronts. A summer and a winter cruise are planned to address seasonal variability. This experiment will provide important new information on the circulation and density fields associated with cross-shelf oriented mesoscale fronts and on interactions between proximate fronts of similar scale. Such fronts may play a central role in shoreward and seaward cross-shelf transport in the coastal ocean. These measurements will explore specific transport mechanisms associated with the Hatteras Front in a particularly energetic region of high off-shelf export and considerable shoreward transport, and permit a dynamical analysis of frontal circulation features. In addition, spatial and temporal correlation scales will be defined, and the magnitude of vertical eddy viscosity associated with the fronts will be estimated, thereby substantially informing future modeling efforts of this oceanographically complex region. The insights gained will be pertinent to studies of material, nutrient, and volume budgets on the continental shelf, to life-history studies of commercially important shelf-spawning, estuarine-dependent species, and to efforts to mitigate commercial fishing-related mortality of marine mammals near Cape Hatteras. The findings of this study will be disseminated through the scientific community through presentations at national meetings and articles published in refereed journals. Two graduate students and one undergraduate will participate in support of the planned field-work. Outreach to the K-12 community will also be possible, through Dr. Savidge's continuing involvement in the National Ocean Sciences Bowl, a question and answer contest for high-schoolers organized by the Consortium for Oceanographic Research and Education (CORE), and by Dr. Garwarkiewicz's involvement with his local Science and Math magnet elementary school, on whose Board of Directors he sits.