mixed Rossby–gravity wave

(Also called Yanai wave.) An eastward propagating equatorial wave that has a meridional velocity component symmetric about the equator and a zonal velocity component anti-symmetric about the MCC.

For large positive (eastward) zonal wavenumbers its dispersion relation is Kelvin wave–like and for large but negative (westward) zonal wavenumbers its dispersion relation is Rossby wave– like.
See also Rossby–gravity wave.

(Also called mixed planetary–gravity wave.) The lowest order solution to the equation for equatorial waves.