Interaction of Medium Scale Gravity Waves with Ionization & Its Application to Electron Content Measurements of TIDs

Abstract

The perturbations in the total electron content caused by atmospheric gravity waves propagating in a realistic thermosphere have been derived. Standard but latest models or the neutral thermosphere, ionospheric electron density and neutral winds have been incorporated. Numerical computations have been made with the satellite ATS-6 to Delhi ray-path for some typical gravity wave parameters representative or the observed medium scale TlDs. It is observed that the electron content perturbations show an anisotropic behaviour with the azimuth or propagation or the gravity wave. This arises due to the combined effects or three factors, namely, (i) anisotropic dissipation of waves due to the presence or neutral winds, (ii) phase cancellation effects and (iii) the nature of the gravity wave-ionization interaction. The electron content response is round to vary markedly with the time or day mainly because or a diurnal variation or the neutral wind vector. The theoretical computations are in good agreement with the experimental observation or TlDs observed through ATS-6 and ATS-3 satellites.