Department of Meteorology

DESCRIPTION FOR FIRST FIVE VARIABLES:

The streamlines in each figure in the left column are shown in a frame of reference which moves at the same (zonal) speed as the wave pouch, and the (zonal) translation speed is indicated at the top of the left column. The right column figures are shown in the earth-relative frame of reference with a zonal speed of 0 m/s.

The purple curve represents the local critical surface, where the zonal flow equals the phase speed of the wave pouch. The black curve is the wave trough axis, where the meridional flow is zero and the relative vorticity is cyclonic. The black circle indicates the center of the pouch.