Project Leader:
Robert Houghton
Description:
Mixing and circulation in the Delaware Coastal Current (DCC), a buoyant coastal jet, will be studied using a combination of numerical modeling and field work (moorings, rapid surveys, and purposeful dye releases) followed by analysis and interpretation of results from the two approaches. Working hypotheses are that mixing between the coastal buoyant discharge and ambient shelf waters is larger during upwelling than downwelling events, that this mixing during upwelling is primarily concentrated at the offshore plume boundary, and that the conservation of buoyancy is principally a balance between horizontal advection and vertical diffusion. Moorings will include standard current meters and bottom-mounted acoustic Doppler current profilers (ADCPs). There will be 5 moorings, three parallel to the DCC and three perpendicular. Multiple conductivity-temperature-depth recorders (CTDs) and temperature sensors will also be deployed on both taut and slack moorings. At the northernmost mooring, two ADCPs will allow estimation of the Reynolds stresses using Stacey's method. ADCP bin spacing will be 0.5 m allowing resolution of 1m eddies. Forty-five kilograms of Rhodamine dye will be released during each upwelling or downwelling event selected for study. This dye will be traced for 4-5 days. There will be two cruises and mooring deployments. One upwelling dye study will occur during year 1 and one upwelling and one downwelling experiment during year two. A previously utilized version of ECOM3d, configured for the DCC, will be used to analyze the dye study results. Significant effort will be devoted to comparing different turbulent closure schemes. After the model is calibrated, it may be used for sensitivity studies. Careful comparison and interpretation of field and model results will conclude the study.
EI Unit:
Lamont-Doherty Earth Observatory (LDEO)
Cross Cutting Themes:
Water
Core Disciplines:
Earth Sciences
Collaborating Institutions:
University of Delaware
Funding Agency:
National Science Foundation
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