Joe LaCasce, University of Oslo, Norway


Topographic effects on ocean eddies


Much of our theory of ocean circulation was developed using idealized models with a flat bottom. This often greatly simplifies the derivations, but including bathymetry can alter things in important ways. For example, baroclinic modes become more surface-intensified over realistic bathymetry. This increases the deformation radius, by 25-50% over much of the ocean. Eddies are therefore larger than previously thought, and propagate faster. Topography also favors lateral ("barotropic") instability at the expense of baroclinic instability. A cosine ridge can effectively block baroclinic instability;
more relalistic 2D bathymetry (bumps) is less effective, but has a similar tendency. Thus lateral instability may be more important than previously thought.


Tuesday October 29, 11:15


Rossbysalen C609, Arrhenius laboratory, Svante Arrhenius väg 16C, 6th floor