HR: 0800h
AN: U11A-0829    [Abstracts]
TI: Modelling and detection of the ionospheric perturbation associated to the Sumatra tsunami of December, 26th, 2004
AU: * Occhipinti, G
EM: occhip@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4 Avenue de Neptune, Saint Maur, 94100 France
AU: * Occhipinti, G
EM: occhip@ipgp.jussieu.fr
AF: Office National d'Etudes et Recherches Aérospatiales, chemin de la Hunière, Palaiseau, 91761 France
AU: Lognonné, P
EM: lognonne@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4 Avenue de Neptune, Saint Maur, 94100 France
AU: Kherani, A
EM: alam@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris, 4 Avenue de Neptune, Saint Maur, 94100 France
AU: Hebert, H
EM: helene.hebert@cea.fr
AF: Commisariat à l'Energie Atomique, BP12, Bruyeres-de-Chatel, 91680 France
AB: The Sumatra, December 26th tsunami has generated large ionospheric signals associated to tsunami-coupled atmospheric gravity waves. These waves were detected by the dual frequency altimeters onboard in the Jason-1 and Topex satellites, as well as by GPS stations in the Indian ocean. They confirmed, following the theory proposed by [Peltier & Hines, 1976] and a first tsunami-ionospheric signal detected after the much smaller tsunami generated by the Peru, June, 23, 2001, the maturity of the modern ionospheric sensitive instruments for detecting these signals.. This perturbation is observed by both satellites, between 2h55 and 3h05 TU and leads to large perturbations in the TEC data. We present here a modelling of these ionospheric perturbations and perform the comparison with observations. The modelling is performed with a realistic 2D modelling of the oceanic tsunami gravity wave, used as atmospheric source, and with a 3D pseudo-spectral modelling of the atmospheric gravity wave. The later is then used for the computation of the ionospheric perturbations. The effects of the different ionospheric parameters (neutral-ion collision frequencies, magnetic field diffusion, etc) are studied and quantified. We then compare observations and simulations. This work allows us to calibrate the efficiency of ionospheric tsunami detection and to assess the signal-to-noise ratio of signals, for different tsunami height. The efficiency of high resolution real time monitoring (satellites and/or ground-space) systems in tsunami detection is then discussed and their inclusion in the existing or future tsunami warning systems proposed.
DE: 0689 Wave propagation (2487, 3285, 4275, 4455, 6934)
DE: 1222 Ocean monitoring with geodetic techniques (1225, 1641, 3010, 4532, 4556, 4560, 6959)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4255 Numerical modeling (0545, 0560)
SC: Union [U]
MN: Fall Meeting 2005