FN Archimer Export Format PT J TI A study of the phase instability of quasi-geostrophic Rossby waves on the infinite beta-plane to zonal flow perturbations BT AF MARIE, Louis AS 1:; FF 1:PDG-DOP-DCB-OPS-LPO; C1 IFREMER, Ctr Brest, CNRS IRD UBO UMR6523, Lab Phys Oceans, F-29280 Plouzane, France. C2 IFREMER, FRANCE SI BREST SE PDG-DOP-DCB-OPS-LPO IN WOS Ifremer jusqu'en 2018 IF 1.3 TC 2 UR https://archimer.ifremer.fr/doc/00008/11903/8612.pdf LA English DT Article AB The problem of the linear instability of quasi-geostrophic Rossby waves to zonal flow perturbations is investigated on an infinite beta-plane using a phase dynamics formalism. Equations governing the coupled evolutions of a zonal velocity perturbation and phase and amplitude perturbations of a finite-amplitude wave are obtained. The analysis is valid in the limit of infinitesimal, zonally invariant perturbation components, varying slowly in the meridional direction and with respect to time. In the case of a slow sinusoidal meridional variation of the perturbation components, analytical expressions for the perturbation growth rates are obtained, which are checked against numerical codes based on standard Floquet theory. PY 2010 SO Nonlinear Processes In Geophysics SN 1023-5809 PU Copernicus Gesellschaft Mbh VL 17 IS 1 UT 000274995600003 BP 49 EP 63 ID 11903 ER EF