[S20-P] Poster

[S20-P-01] Atmospheric interior resonances : theory and observation on Earth and comparative analysis for terrestrial planets with atmosphere

^○Philippe Lognonne^{1, 2}, Virgile Rakoto^{1, 2}, Foivos Karakostas^1,2, Lucile Rolland³, Elvira Astafyeva¹, Balthasar Kenda^1,2,3, Yasuhiro Nishikawa^1,2 (1.Institut de Physique du Globe de Paris-Sorbonne Paris Cite, Paris, France, 2.Universite Paris Diderot, Paris, France, 3.GeoAzur, Observatoire de la Cote d'Azur, Valbonne, France, 4.Jet Propulsion Laboratory, Pasadena, USA)

Resonance effects occur with the atmosphere when the dispersion curves of the Earth interior normal modes cross or are close from atmospheric dispersion curves. On Earth, this occurs for example between the Rayleigh surface waves branch and the acoustic branches and between the tsunami branch and the atmospheric gravity branches.
These resonances are not always retrieved in the atmospheric signals, as the later depend not only on the coupling with the atmosphere as a whole, but also on the location of the sensor (for in situ observation) or of the sounding zone (for remote sensing observation). We illustrate this altitude effects with both theoretical examples and observations, noting that ionospheric observation, because of their altitude, are mostly sensitive to the resonances associated no non atmospheric trapped resonances. Observations shown are either related to Rayleigh waves (with Doppler and GPS sounders) or to tsunamis (mostly with GPS-TEC). We also discuss how the strength of these resonances changes with Local Time, as well as with other changes in the atmospheric structure.
We then conclude by a comparative analysis of the resonances effects on other terrestrial planets, focusing on Venus, Mars and Titan, and discuss the expected impacts of these resonances for future atmospheric ionospheric seismic observation on these bodies. We especially discuss the impact of the coupling on Venus, which is strong enough to modify significantly the attenuation factors and group velocity of Rayleigh waves in contrary to the Earth case, where such perturbations remain small for both Rayleigh and Tsunamis.