Acoustic thermometry of the western Mediterranean basin

Ocean acoustic tomography is used to obtain heat-content estimates for the western Mediterranean basin. Travel-time data from 13 tomography sections of the Thetis-2 experiment (January–October 1994) are analyzed with a matched-peak inversion approach. The underlying analysis involves the use of peak arrivals and nonlinear model relations between travel-time and sound-speed variations. Slice inversion results are combined with temperature covariance functions for the western Mediterranean to obtain heat-content estimates for the basin. These estimates compare favorably with ECMWF data over the nine-month period of the Thetis-2 experiment. Furthermore, estimates for the basin-average temperature of the western Mediterranean deep water are obtained.