Abstract

Space-borne observations of thermospheric temperature, wind, and airglow measurements, as well as ionosphereric density and drift diagnostics exhibit longitudinal variations during geomagnetically quiescent conditions that may be attributable to nonmigrating tidal effects. We carried out a series... Show moreSpace-borne observations of thermospheric temperature, wind, and airglow measurements, as well as ionosphereric density and drift diagnostics exhibit longitudinal variations during geomagnetically quiescent conditions that may be attributable to nonmigrating tidal effects. We carried out a series of numerical experiments with the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-mesosphere- electrodynamics general circulation model (TIME-GCM), to investigate the impact of nonmigrating tides on the Earth's thermosphere and ionosphere. We forced the NCAR TIME-CGM lower boundary (ca., 30km) with global- scale wave model (GSWM) tidal perturbations to account for tropospheric tides excited by latent heat release associated with raindrop formation in deep convective tropical towers and explored the evolution of these waves as they propagated upward in the model domain. Our results show that some of these waves interact with the migrating tidal components and generate secondary tidal waves as well as stationary planetary waves that modulate the E-region dynamo. We characterize their impact on the thermosphere and ionosphere aloft and provide a context for further interpretations of satellite measurements. Show less