Connections between deep tropical clouds and the Earth's ionosphere

We report on a series of simulations with the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) which were designed to replicate and facilitate the interpretation of the longitudinal structure discovered in IMAGE satellite airglow observations of the equatorial ionization anomaly (EIA) at the far-ultraviolet (FUV) 135.6-nm wavelength during March-April 2002 equinox.

Our TIME-GCM results indicate that the four-peaked longitudinal variation in the EIA observed by IMAGE-FUV near 20:00 local solar time can be explained by the effects of an eastward propagating zonal wavenumber-3 diurnal tide (DE3) that is excited by latent heat release associated with raindrop formation in the tropical troposphere.