Modelling atmospheric and induced non-tidal oceanic loading contributions to surface gravity and tilt measurements

Jean-Paul Boy , Laurent Longuevergne , Frédéric Boudin , Thomas Jacob , Florent Lyard , Muriel Llubes , Nicolas Florsch , Marie-France Esnoult

We investigate the contribution of atmospheric and its induced non-tidal oceanic loading effects on surface time-varying gravity and tilt measurements for several stations in Western Europe. The ocean response to pressure forcing can be modelled accordingly to the inverted barometer, i.e. assuming that air pressure variations are fully compensated by static sea height changes, or using ocean general circulation models. We validate two runs of the HUGO-m barotropic ocean model by comparing predicted sea surface height variations with hundred tide gauge measurements along the European coasts. We then show that global surface pressure field, as well as a barotropic high-resolution ocean model forced by air pressure and winds allow in most cases a significant reduction of the variance of gravity residuals and, to a smaller extends tilt residuals.

Mots clés: Atmospheric loading; non-tidal oceanic loading; superconducting gravimeters; hydrostatic tiltmeters; storm surges

Jean-Paul Boy, Laurent Longuevergne, Frédéric Boudin, Thomas Jacob, Florent Lyard, et al.. Modelling atmospheric and induced non-tidal oceanic loading contributions to surface gravity and tilt measurements. Journal of Geodynamics, 2009, 48 (3-5), pp.182. ⟨10.1016/j.jog.2009.09.022⟩. ⟨hal-00594413⟩