Generation of large-scale gravity waves and neutral winds in the thermosphere from the dissipation of convectively generated gravity waves

Those small-and medium-scale GWs which reach the thermosphere dissipate at z similar to 120-250 km in a direction opposite to the background wind similar to(1-2) density scale heights below. This localized momentum deposition creates horizontal thermospheric body forces that have large sizes and amplitudes and generates large-scale secondary GWs and large-scale traveling ionospheric disturbances (LSTIDs) that propagate globally away from the body force in all directions except that perpendicular to the force direction.

For the convective plume at 2120 UT, the secondary GWs have horizontal wavelengths of lambda(H) similar to 2100-2200 km, periods of tau(r) similar to 80 min, horizontal phase speeds of c(H) similar to 480-510 m/s, density perturbations as large as vertical bar rho'/(rho) over bar vertical bar similar to 3.6-5% at z = 400 km, relative [O] perturbations as large as similar to 2-2.5% at z = 300 km, and total electron content perturbations as large as similar to 8%.