Differential Diffusion in Bistable Conditions

Abstract

Double diffusive phenomena, due to the difference in molecular conduction coefficients for heat and for ion concentrations in sea water, are widely known. These include salt fingering and diffusive convection which occur when either temperature or salinity is destabilizing while the other (salinity or heat) is stabilizing. Less well known, less dramatic in their occurrence, but far more widespread are circumstances where both temperature and salinity are stabilizing and yet the differences in molecular conduction lead to systematic differences in turbulent transport rates. "Differential diffusion" has been seen in laboratory experiments, in ocean observations and in numerical simulations. Here we examine differential diffusion in terms of turbulence-induced restratifying (up-gradient) fluxes.

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Document Details

Document Type
Technical Report
Publication Date
Jan 19, 2001
Accession Number
ADP013594

Entities

People

  • Ann Gargett
  • Bill Merryfield
  • Greg Holloway

Organizations

  • Institute of Ocean Sciences

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Buoyancy
  • Coefficients
  • Diffusion
  • Dissipation
  • Froude Number
  • Mixing
  • Observation
  • Oceans
  • Reynolds Number
  • Salinity
  • Sea Water
  • Simulations
  • Spectra
  • Stratified Fluids
  • Technical Information Centers
  • Turbulence
  • Turbulent Mixing

Readers

  • Fluid Dynamics.
  • Groundwater Contamination Remediation.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers