Article
 

Effects of keels on ice bottom turbulence exchange

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/9c67wp42s

Descriptions

Attribute NameValues
Creator
Abstract
  • The effects of ice keels on the upper ocean are examined using a combination of turbulence measurements and output from a large-eddy simulation (LES) model. Two cases are examined, one during the winter when the under-ice boundary layer is relatively deep (~20 m) and near the freezing point and a second during the summer when the ice is melting and the boundary layer consists of a shallow (~0.5 m), highly stratified fresh layer. In the winter case, measurements show that flow disruption by a 10-m-deep keel causes enhanced vertical mixing, increasing the heat flux from a background value of ~5 W m^(-2) to values averaging ~25 W m^(-2). Simulations using the LES model are in good agreement with the measurements and indicate that the keel generates a turbulent wake region extending hundreds of meters downstream from the keel. Elevated heat fluxes in the wake region are generated by increased entrainment of warmer water from beneath the mixed layer. Simulations of summer cases demonstrate that shallow keels (~0.5 m) generate strong turbulence that is able to rapidly mix the fresh layer in the lee of keels. However, this effect decreases quickly as the fresh layer accelerates to match the ice velocity. Deeper keels (1 m) follow a similar pattern but generate more mixing as the fresh layer is forced under the keel. Simulated ice melt heat fluxes are similar to estimates made from ice balance measurements taken during the Surface Heat Budget of the Arctic Ocean summer field program.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Skyllingstad, E. D., Paulson, C. A., Pegau, W. S., McPhee, M. G., & Stanton, T. (2003). Effects of keels on ice bottom turbulence exchange. Journal of Geophysical Research, 108(C12). doi:10.1029/2002JC001488
Journal Title
Journal Volume
  • 108
Rights Statement
Funding Statement (additional comments about funding)
  • National Science Foundation funded the use of the supercomputer of the National Center of Atmospheric Research. This work was supported as part of the Surface Heat Budget of the Arctic (SHEBA) project. National Science Foundation grants OCE-97-03539, OPP-00-84284. Office of Naval Research grant N00014-01-1-0022/ORSC.
Publisher
Language
Replaces
ISBN
  • 10.1029/2002JC001488

Relationships

Parents:

This work has no parents.

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Skyllingstad_et_al_JGR_2003.pdf 2017-07-24 Public Download