HYDROGRAPHIC CONDITIONS OF THE IBIZA CHANNEL DURING NOVEMBER 1990, MARCH 1991 AND JULY 1992

The hydrographic conditions of the Ibiza Channel were studied in succe ssive surveys during November 1990, March 1991 and twice in July 1992. From a hydrographic viewpoint we must emphasize the importance of the intrusion of Modified Atlantic Water (MAW) with its associated front as a result of mesoscale processes, and the presence of the seasonal W inter Intermediate Water (WIW) which fills the entire width of the cha nnel in the form of a layer between 300 or 400 m thick. This water mas s affects the dynamics of the Ibiza Channel by a reduction in the exch ange, hiding the seasonal characteristics of the Levantine Intermediat e Water (LIW), which we consider to be one of the causes of the circul atory change in the channel. The combined action of the different wate r masses and their production cycles give rise to readjustments in den sity that could favour the presence of gradients on the continental sl opes and Deep Water (DW) on the sill of the Channel. The geostrophic t ransports of the different water masses have been calculated.