Planetary wave coupling of the mesosphere-lower thermosphere-ionosphere (MLTI) region during deep solar minimum 2005-2008

Abstract

The present study investigates the role of planetary-scale waves in the mesosphere-lower thermosphere-ionosphere (MLTI) coupling during the deep solar minimum period of 2005-2008. In the absence of severe magnetic disturbances, it is expected that much of the observed variations in low latitude ionospheric current system, the equatorial electrojet (EEJ), in particular, is expected to be driven by global scale waves propagating from below. The availability of continuous wind data from MF radar at mesospheric heights and geomagnetic field variations, the latter providing a measure of the strength of the ionospheric current system provides a unique opportunity to investigate the role of planetary-scale waves in driving the variabilities in the ionospheric current system during this solar minimum epoch. The study presents interesting findings on the role of planetary waves, especially the 3.5-day ultra-fast Kelvin wave and the 6.5-day wave in the low latitude MLTI coupling.