Penetration of gravity waves into the F region from the lower atmosphere at low and mid latitudes
NorthWest Research Associates, CoRA division, Boulder, Colorado, USA
In this talk, I will discuss the generation, propagation, and dissipation of gravity waves excited by convection at equatorial and mid-latitudes. This talk will be theoretical in nature, and will involve the use of two models, one for the generation of gravity waves by convection, and the other for the ray tracing of gravity waves into the thermosphere through realistic temperatures and winds. The ray trace model now includes gravity wave phases from convection, thereby allowing for the reconstruction of the gravity wave field at any altitude. I will show that because of dissipative filtering in the thermosphere, differing portions of the initial convective spectrum survive to differing altitudes in the thermosphere. I will also show that the background, neutral winds play a key role in establishing the direction of propagation of gravity waves in the thermosphere at the bottomside of the F layer. I will also show that those gravity waves from convection which propagate to the bottomside of the F layer have horizontal scales of 100-400 km. Finally, I will display the amplitudes of the dominant, convectively-generated gravity waves at the bottomside of the F layer.