Frontal Instabilities in a Buoyant Plume

Abstract

Many phenomena in the coastal ocean produce surface signatures that appear in remotely sensed images. We are interested in understanding the dynamics that control these phenomena, particularly those seen in Synthetic Aperture RADAR (SAR) images. Some of the signatures in SAR images are associated with convergence fronts produced by buoyant plumes. Fresh water discharges from rivers and bays into the saltier shelf water can form such plumes. The plumes and the associated fronts can extend for hundreds to thousands of meters and have widths of meters to tens of meters. The plumes can propagate tens to a hundred of kilometers from their source. We used three models to simulate buoyant jets: a 2.D nonhydrostatic channel model, a 3-D nonhydrostatic Large Eddy Simulation (LES) model and a 3-D hydrostatic model. The hydrostatic model is the Navy Coastal Ocean Model (NCOM) which is a component of the Coupled Ocean Atmosphere Prediction System (COAMPS). The LES model separates the flow by physical scales rather into mean and turbulent components. The nonhydrostatic models simulated the "Lock Exchange" problem using idealized geometries at relatively small scales. The hydrostatic models simulates the Chesapeake Bay outflow plume using realistic topography and geometry.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Dec 05, 1998
Accession Number
ADA379451

Entities

People

  • Michael Schaferkotter
  • Patrick C. Gallacher
  • Paul J. Martin

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Bays
  • Channel Models
  • Chesapeake Bay
  • Dynamics
  • Equations
  • Fluids
  • Fresh Water
  • Geometry
  • Grids
  • Instability
  • Large Eddy Simulation
  • Synthetic Aperture Radar
  • Three Dimensional
  • Topography
  • Turbulent Mixing
  • Two Dimensional
  • Water

Readers

  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Radar Systems Engineering.