Geostrophic adjustment on the equatorial beta-plane revisited


The process of geostrophic adjustment of localized large-scale pressure anomalies in the standard adiabatic shallow-water model on the equatorial beta-plane is revisited, and it is shown that the standard scenario of generation of westward-moving Rossby and eastward-moving Kelvin waves, which underlies the classical Gill theory of tropical circulation due to a localized heating, is not unique. Depending on the strength and aspect ratio of the initial perturbation, the response to the initial perturbation in the western sector can be dominated by inertia-gravity waves. The adjustment in the diabatic moist-convective shallow water model can be totally different and produces, depending on parameters, either Gill-like response or eastward-moving coherent dipolar structures of the type of equatorial modons, which do not appear in the “dry” adjustment, or vortices traveling, respectively, northwest in the Northern and southwest in the Southern hemispheres.


url Accessed 8 times | Last updated 27.01.2020


Rostami, M., Zeitlin, V. (2019): Geostrophic adjustment on the equatorial beta-plane revisited. American Institute of Physics (AIP) – In: Physics of Fluids , Vol. 31(081702), DOI: doi: 10.1063/1.5110441

Authors Rostami, M. and Zeitlin, V.
Type article
Title Geostrophic adjustment on the equatorial beta-plane revisited
DOI doi: 10.1063/1.5110441
Journal Physics of Fluids
Year 2019
Volume 31
Number 081702
Publisher American Institute of Physics (AIP)
Month August
Export BibTeX
Back to dataset list