Research

Rossby waves in the north Atlantic

Previous studies showed that bottom topography and background currents play important roles in modifying the propagation characteristics of baroclinic Rossby waves. However, since the theories used in these studies assume, for example, plane waves or WKBJ approximation, it is not straightforward to apply or extend these theories to forced and damped basin-scale Rossby waves under realistic bathymetry and stratification.

I am analyzing the results of MPI-OM (forced by NCEP atmospheric forcing) using the theoretical framework proposed by Shimizu (2011). It employs the standard vertical modes (flat bottom, no background currents), and derives the governing equations for individual vertical modes. This enables us to analyze Rossby wave dynamics under large topographic effects, forcing, and damping. The theory is limited to linear case in the paper, but it is being extended to a fully nonlinear case.