• Altman, D. B., and A. E. Gargett, 1987: Differential property transport due to incomplete mixing in a stratified fluid. Proc. Third Int. Symp. on Stratified Flows, Pasadena, CA, California Institute of Technology.

  • De Silva, I. P. D., and H. J. S. Fernando, 1992: Some aspects of mixing in a stratified turbulent patch. J. Fluid Mech.,240, 601–625.

  • Dillon, T. M., 1982: Vertical overturns: A comparison of Thorpe and Ozmidov length scales. J. Geophys. Res.,87, 9601–9613.

  • Gargett, A. E., and G. Holloway, 1992: Sensitivity of the GFDL ocean model to different diffusivities for heat and salt. J. Phys. Oceanogr.,22, 1158–1177.

  • Gibson, C. H., 1982: Alternative interpretation for microstructure patches in the thermocline. J. Phys. Oceanogr.,12, 374–383.

  • Hebert, D., N. Oakey, and B. Ruddick, 1990: Evolution of a Mediterranean salt lens: Scalar properties. J. Phys. Oceanogr.,20, 1468–1483.

  • Holyer, J. Y., 1983: Double-diffusive interleaving due to horizontal gradients. J. Fluid Mech.,137, 347–362.

  • Horne, E. P. W., 1978: Interleaving at the subsurface front in the slope water off Nova Scotia. J. Geophys. Res.,83, 3659–3671.

  • Joyce, T. M., W. Zenk, and J. M. Toole, 1978: The anatomy of the Antarctic polar front in the Drake Passage. J. Geophys. Res.,83, 6093–6113.

  • McDougall, T. J., 1985: Double-diffusive interleaving. Part I: Linear stability analysis. J. Phys. Oceanogr.,15, 1532–1541.

  • Moum, J. N., 1996: Energy-containing scales of turbulence in the ocean thermocline. J. Geophys. Res.,101, 14 095–14 109.

  • Ruddick, B., 1983: A practical indicator of the stability of the water column to double-diffusive activity. Deep-Sea Res.,30, 1105–1107.

  • ——, 1992: Intrusive mixing in a Mediterranean salt lens—Intrusion slopes and dynamics mechanisms. J. Phys. Oceanogr.,22, 1274–1285.

  • ——, and D. Hebert, 1988: The mixing of Meddy “Sharon.” Small-Scale Mixing in the Ocean, J. C. J. Nihoul and B. M. Jamart, Eds., Elsevier Oceanography Series, Vol. 46, Elsevier, 249–262.

  • Stern, M. E., 1967: Lateral mixing of water masses. Deep-Sea Res.,14, 747–753.

  • Sullivan, G. D., and E. J. List, 1994: On mixing and transport at a sheared density interface. J. Fluid Mech.,273, 213–239.

  • Sun, H., E. Kunze, and A. J. Williams III, 1996: Vertical heat-flux measurements from a neutrally buoyant float. J. Phys. Oceanogr.,26, 984–1001.

  • Toole, J. M., and D. T. Georgi, 1981: On the dynamics and effects of double-diffusively driven intrusions. Progress in Oceanography, Vol. 10, Pergamon, 123–145.

  • Turner, J. S., 1968: The influence of molecular diffusivity on turbulent entrainment across a density interface. J. Fluid Mech.,33, 639–656.

  • ——, 1973: Buoyancy Effects in Fluids. Cambridge University Press, 368 pp.

  • Walsh, D., and B. Ruddick, 1995: Double-diffusive interleaving: The influence of nonconstant diffusivities. J. Phys. Oceanogr.,25, 348–358.

  • ——, and ——, 1998: Nonlinear equilibrium of thermohaline intrusions. J. Phys. Oceanogr.,28, 1043–1070.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 186 186 3
PDF Downloads 16 16 0

Intrusions: What Drives Them?

View More View Less
  • 1 Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

The driving mechanism for the observed interleaving of water masses is generally assumed to be double-diffusive mixing. However, some observations of intrusions have been made in regions where the mean stratification is stable to double-diffusive mixing. It has been hypothesized that a finite amplitude disturbance must occur to produce regions where the stratification allows double-diffusive mixing or that an instability due to differences in the molecular diffusivity of salinity and temperature produces the desired stratification for double-diffusive mixing to start. There is also the possibility of a differential vertical flux of salt and heat due to incomplete mixing by turbulence. The basis of this idea is described in this paper. Growth rates, vertical scales, and cross-frontal slopes of intrusions predicted by this process are compared to those predicted by double-diffusive mixing.

Corresponding author address: Dr. Dave Hebert, Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882-1197.

Email: hebert@gso.uri.edu

Abstract

The driving mechanism for the observed interleaving of water masses is generally assumed to be double-diffusive mixing. However, some observations of intrusions have been made in regions where the mean stratification is stable to double-diffusive mixing. It has been hypothesized that a finite amplitude disturbance must occur to produce regions where the stratification allows double-diffusive mixing or that an instability due to differences in the molecular diffusivity of salinity and temperature produces the desired stratification for double-diffusive mixing to start. There is also the possibility of a differential vertical flux of salt and heat due to incomplete mixing by turbulence. The basis of this idea is described in this paper. Growth rates, vertical scales, and cross-frontal slopes of intrusions predicted by this process are compared to those predicted by double-diffusive mixing.

Corresponding author address: Dr. Dave Hebert, Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882-1197.

Email: hebert@gso.uri.edu

Save