Geopotential height is scaled by the maximal height. Colours vary between -1 and +1 with positive/negative perturbations in red/blue.
Wind components are scaled by the maximal wind speed. The equivalent depth is 1536 meters.
Mixed Rossby-gravity (MRG) wave is the equatorially-trapped mode which together with the Kelvin wave fills the frequency gap between the Rossby and gravity modes in the tropics.
As its zonal wavenumber increases, the MRG wave becomes increasingly more rotational mode.
In the case of linearized equations on the equatorial beta-plane, the mixed Rossby-gravity wave is denoted the westward-propagating MRG mode.