English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Interpreting layer thickness advection in terms of eddy–topography interaction

MPS-Authors
There are no MPG-Authors available
Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Liu, C., Köhl, A., & Stammer, D. (2014). Interpreting layer thickness advection in terms of eddy–topography interaction. Ocean Modelling, 81, 65-77. doi:10.1016/j.ocemod.2014.07.001.


Cite as: http://hdl.handle.net/11858/00-001M-0000-0024-63B4-A
Abstract
A parameterization for the spatial pattern of the eddy induced thickness advection parameter estimated from a dynamically consistent data assimilation procedure is presented. Values of the thickness advection parameter are predominantly negative (positive) over seamounts, and positive (negative) over the deep ocean in the southern (northern) hemisphere along strong currents; its magnitude is large at high latitudes but low in the tropical regions. Those characteristics motivate a parameterization based on the Coriolis parameter, the bottom depth and an eddy length scale. As a parameterization for an eddy streamfunction, the associated bolus velocities advect density anti-cyclonically (cyclonically) around seamounts (troughs). Although the parameterization has the same form as Holloway’s streamfunction for the Neptune effect, and is also related to eddy–topography interactions, Holloway’s streamfunction is in contrast applied to the momentum equation. The parameterization is independently confirmed by the flux-mean gradient relation from the output of a high resolution model. The effect of the proposed scheme is investigated using a channel model with idealized bottom topographies and a global ocean circulation model with realistic bottom topography. In agreement with the high resolution model, our scheme generates cold (warm) domes and cyclonic circulations over seamounts (troughs), which is consistent with the eddy movement in presence of the topographic β effect. This provides a different mechanism for eddy–topography interaction than the Neptune effect, which generates circulations of opposing sign.