TitleImpact of cross-shelf winds and estuarine/coastal ocean coupling on buoyant plume systems
NameJurisa, Joseph Thomas (author), CHANT, ROBERT J (chair), Wilkin, John L. (internal member), Glenn, Scott M. (internal member), Geyer, W. Rockwell (outside member), Rutgers University, Graduate School - New Brunswick,
Plumes (Fluid dynamics) ,
DescriptionObservational data and realistic and idealized model simulations are used to examine the impact of variable winds, topography, and shelf circulation on a buoyant river plume/estuarine system. Observational data collected during the spring of 2006 Lagrangian Transport and Transformation Experiment (LaTTE) on the New Jersey coast suggest a strong interaction between the variable wind and buoyant forcing and the shelf circulation. During a 2-week field campaign the coastal current detached from the coast and formed a recirculating eddy 60 km downstream of the outflow. This eddy was persistent for 2 weeks under variable wind forcing, as was observed from mooring, shipboard, and satellite data and also from model hindcasts. The formation of the feature is dependent on the estuarine discharge, with cross-shore winds also playing a vital role. To provide a more generalized view of the role of cross-shelf winds, idealized simulations are run with a straight coastline, linearly sloping bathymetry, and a straight channel as an estuary. It is found that during an offshore wind stress that the plume is initially transported offshore, but after a couple inertial periods it reaches a steady state in terms of its cross-shore salinity and velocity structure and offshore position. This steady state structure is highly dependent on the estuarine outflow conditions, with the offshore position described by a ratio of the estuarine outflow Froude number and a plume Froude number. Formulations for the plume properties are also developed. The steady state nature of the plume’s response to the cross-shore winds is examined by analyzing the mixing in the plume using a salinity coordinate system. These results and theories developed using the idealized model simulations are compared to realistic model hindcast simulations of the Hudson River plume during the 2005/2006 winter season, when offshore winds are dominant. The response of the Hudson River plume generally compares with the idealized model results, with a few exceptions due to the complex geometry of the New York Bight. This response is a departure from the assumed downwelling response, and has implications for salinity induced stratification over inner shelf during the winter season.
NoteIncludes bibliographical references
Noteby Joseph Thomas Jurisa
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.