The role of winter intermediate waters in the spring-summer circulation ofthe Balearic Sea - 1. Hydrography and inverse box modeling

Hydrographic transects performed across the Balearic Sea (western Mediterra nean) in June 1993 are used to estimate the absolute geostrophic flow by me ans of a linear inverse model, ensuring conservation of water properties (m ass, salt, and heat) in closed boxes. The computed fluxes are supporting th e concept that most of the northern waters that flow into the basin over th e Spanish peninsula slope (approximate to 1.1 Sv) recirculate back to the n orth in a cyclonic pattern while southern waters that enter through the Ibi za Channel, mainly modified Atlantic waters (approximate to 0.5 Sv), transi t to the north over the Balearic slope, Results point out that winter inter mediate waters (WIW), distributed in several coherent mesoscale structures, play an active role in these dynamics. A major anticyclonic WIW eddy ("wed dy") lying in the southern basin obstructs the water exchange through the I biza Channel and deflects the Continental Current back to the north, A simi lar though smaller weddy, strained by the Balearic Current into an elongate d along-slope WIW filament, controls the circulation through the Mallorca C hannel. All these results are discussed in the light of data collected duri ng past years.