Group velocity and energy transport by Rossby waves
Abstract
A variational method gives a proof that for normal modes of Rossby waves in the ocean on a betaplane with depth variable in the meridional direction, the time average of the energy flux defined as the product of the pressure and the fluidparticle velocity agrees with the time average of the energy density multiplied by the group velocity. This conclusion holds in considerably general situations and sheds light on the controversial problem of the energy transport by Rossby waves. Moreover, the variational method gives a remarkable relation between the group velocity and the phase velocity. In particular this relation shows that the absolute value of the group velocity never exceeds that of the phase velocity.
 Publication:

Oceanographical Society of Japan Journal
 Pub Date:
 February 1978
 Bibcode:
 1978OSJaJ..34....1M
 Keywords:

 Energy Transfer;
 Group Velocity;
 Rossby Regimes;
 Transport Theory;
 Water Waves;
 Gravity Waves;
 Mathematical Models;
 Meteorology;
 Oceanography;
 Phase Velocity;
 Wave Propagation;
 Fluid Mechanics and Heat Transfer