Numerical modeling of the large-scale neutral and plasma responses to the body forces created by the dissipation of gravity waves from 6 h of deep convection in Brazil

We study the response of the thermosphere and ionosphere to gravity waves (GWs) excited by 6h of deep convection in Brazil on the evening of 01 October 2005 via the use of convective plume, ray trace, and global models. We find that primary GWs excited by convection having horizontal wavelengths of (H)approximate to 70-300km, periods of 10-60min, and phase speeds of c(H)approximate to 50-225m/s propagate well into the thermosphere. Their density perturbations are rho'/(rho) over bar approximate to 15- 25% at z approximate to 150km and are negligible at z>300km. The dissipation of these GWs creates spatially and temporally localized body forces with amplitudes of 0.2- 1.0 m/s(2)at z approximate to 120-230km. These forces generate two counter-rotating circulation cells with horizontal velocities of 50-350m/s. They also excite secondary GWs; those resolved by our global model have (H)approximate to 4000-5000km and c(H)approximate to 500-600m/s. These secondary GWs propagate globally and have rho'/(rho) over bar approximate to 10- 25% and 5-15% at z=250 and 375km, respectively. These forces also create plasma perturbations of f(o)F2 approximate to 0.2-1.0MHz, TEC approximate to 0.4- 1.5TECU (total electron content unit, 1TECU =10(16) elm(-2)), and h(m)F2 approximate to 5-50km. The large-scale traveling ionospheric disturbances (LSTIDs) induced by the secondary GWs have amplitudes of f(o)F2 approximate to 0.2-0.5MHz, TEC approximate to 0.2- 0.6 TECU, and h(m)F2 approximate to 5-10km. In a companion paper, we discuss changes to the prereversal enhancement and plasma drift from these forces.