Latent heating is the most significant non-migrating tidal source. Future GSWM standards will include latent heating and EUV effects. Back to Top of Model page. Dissipation Upward propagatig tidal amplitudes increase with altitude as the density of the atmosphere decreases, however wave dissipation effects become important in the middle and upper atmosphere. GSWM accounts for a number of tidal dissipation effects as highlighted below.
Gravity waves deposit momentum in the mesosphere and lower thermosphere as they break.
There are significant mean wind and diurnal tidal effects, due to the comparatively short vertical wavelength of the diurnal tide. The figure shows the GSWM coefficients for solstice conditions. The equivalent equinoctal coefficients are an order of magnitude smaller. The turbulence generated by breaking or dissipating gravity waves generates diffusion effects which are felt by all tidal fields. Illustrations of GSWM January and April eddy diffusion coefficients indicate the magnitude of the altitudinal, latitudinal, and seasonal variations associated with this dissipative effect.