IUGG 2003 Abstract

P03 The Role of Tides, Mesoscale Processes, and Bottom Topography in Energy Transfer and Mixing Tuesday, July 1 PM Location: Site B, Room 19 Presiding Chair:E. Morozov

TIME [ 1440 ] [ P03/01P/B19-003 ]

EVIDENCE OF STRONG INERTIA-GRAVITY WAVE ACTIVITY DURING POMME EXPERIMENT

Pascale BOURUET-AUBERTOT(LODYC, Universite Pierre et Marie Curie)

Herle MERCIER(LPO/Ifremer) Fabienne GAILLARD ( LPO/Ifremer ) Pascale LHERMINIER ( LPO/Ifremer )

The purpose of this paper is to characterize inertia-gravity waves(hereafter igw) activity and to investigate the variability ofthese waves in relationship with larger scale motions and surfaceforcing. To this aim we analyzed eulerian measurements ofhorizontal currents and temperature collected during one yearduring POMME experiment. As expected the shape and level of energyspectra varies depending on the strength of the stratification.For weak stratification the slope of the energy spectra is almostconstant for supra-inertial frequencies. By contrast for strongerstratification discrete frequencies, mainly f and M2, dominate thespectra at the lowest frequencies of the igw domain. Timeevolution of the relative energy of these two components giveevidence of isolated events of high intensity. We tried toidentify the mechanism of generation of these waves of highamplitude using both surface fluxes and the mesoscale eddy fieldinferred from a quasi-geostrophic model. We eventually discuss theimpact of these events on vertical mixing.