Records
Links
Author
Ali, A. ; Christensen, K.H. ; Breivik, Ø. ; Malila, M. ; Raj, R.P. ; Bertino, L. ; Chassignet, E.P. ; Bakhoday-Paskyabi, M.
Title
A comparison of Langmuir turbulence parameterizations and key wave effects in a numerical model of the North Atlantic and Arctic Oceans
Type
$loc['typeJournal Article']
Year
2019
Publication
Ocean Modelling
Abbreviated Journal
Ocean Modelling
Volume
137
Issue
Pages
76-97
Keywords
Langmuir mixing parameterization Mixed layer depth Sea surface temperature Ocean heat content Stokes penetration depth
Abstract
Five different parameterizations of Langmuir turbulence (LT) effect are investigated in a realistic model of the North Atlantic and Arctic using realistic wave forcing from a global wave hindcast. The parameterizations mainly apply an enhancement to the turbulence velocity scale, and/or to the entrainment buoyancy flux in the surface boundary layer. An additional run is also performed with other wave effects to assess the relative importance of Langmuir turbulence, namely the Coriolis-Stokes forcing, Stokes tracer advection and wave-modified momentum fluxes. The default model (without wave effects) underestimates the mixed layer depth in summer and overestimates it at high latitudes in the winter. The results show that adding LT mixing reduces shallow mixed layer depth (MLD) biases, particularly in the subtropics all year-around, and in the Nordic Seas in summer. There is overall a stronger relative impact on the MLD during winter than during summer. In particular, the parameterization with the most vigorous LT effect causes winter MLD increases by more than 50% relative to a control run without Langmuir mixing. On the contrary, the parameterization which assumes LT effects on the entrainment buoyancy flux and accounts for the Stokes penetration depth is able to enhance the mixing in summer more than in winter. This parametrization is also distinct from the others because it restrains the LT mixing in regions of deep MLD biases, so it is the preferred choice for our purpose. The different parameterizations do not change the amplitude or phase of the seasonal cycle of heat content but do influence its long-term trend, which means that the LT can influence the drift of ocean models. The combined impact on water mass properties from the Coriolis-Stokes force, the Stokes drift tracer advection, and the wave-dependent momentum fluxes is negligible compared to the effect from the parameterized Langmuir turbulence.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
1463-5003
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1001
Permanent link to this record
Author
Bourassa, M. A.
Title
Satellite-based observations of surface turbulent stress during severe weather
Type
$loc['typeJournal Article']
Year
2006
Publication
Atmosphere-Ocean Interactions
Abbreviated Journal
Volume
2
Issue
Pages
35-52
Keywords
Abstract
Address
Corporate Author
Thesis
Publisher
Wessex Institute of Technology
Place of Publication
Editor
Perrie, W.
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
ISBN
Medium
Area
Expedition
Conference
Funding
FYAP, NASA, NOAA, NSF
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
914
Permanent link to this record