Modeling the effects of tropospheric tides on the ionosphere

Recent modeling studies performed with the NCAR thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) have shown that tides of tropospheric origin are capable of affecting the thermosphere and ionosphere and can explain the wave-four longitudinal structure that has been observed in the equatorial ionization anomaly (EIA). The eastward propagating zonal wavenumber-3 diurnal tide (DE3) has a particularly strong signature that peaks near 110 km and penetrates into the upper thermosphere. In this study, we couple the TIME-GCM thermosphere with NRL's comprehensive 3D ionosphere model, SAMI3, in order to investigate the impact of non-migrating tides on the E- and F-region ionosphere. SAMI3 includes a potential equation to self-consistently solve for the electric field. Simulation runs have been performed for March equinox and June solstice conditions at solar minimum (F10.7 = 75.) The SAMI3 results are compared with TIME-GCM as well as with measurements of electron density and electric fields.