First Time Estimation of Thermospheric Neutral Density Profiles From Seed Perturbations of ESF Triggering: A Novel Evidence for Ionosphere Thermosphere Coupling

The present study reveals the coupling between the neutral densities, derived from the Global Ultraviolet Imager satellite and the requisite gravity wave seed perturbations for equatorial spread F occurrence (Manju et al., 2016, https://doi.org/10.1016/j.asr.2015.12.019), derived from the ionosonde data at Trivandrum (8.5\textdegreeN, 77\textdegreeE). Further, the relation between the above two parameters is found to have solar flux dependence. The solar activity variations of the coefficients of the empirical relations between the neutral density profiles and the characteristic curves of equatorial spread F triggering have been found out, and general empirical models to estimate the thermospheric neutral densities are established for all seasons. The present model output shows reasonable agreement with the Naval Research Laboratory-Mass Spectrometer and Incoherent Scatter radar model and Global Ultraviolet Imager-derived neutral density. The study is relevant since it brings out strong ion-neutral coupling prevailing in the ionosphere thermosphere system.