Seasonal and Interannual Variability in a Model of the Mediterranean under Derived Flux Forcing

Abstract

A 100-yr integration of a Mediterranean Sea model is performed with surface restoring to monthly varying T, S, followed by 100 years of integration with surface fluxes of heat and freshwater alone. The fluxes are diagnosed from the restoring boundary run and are shown to agree favorably with the observations. The model properties remain stable under flux forcing, reproducing all major water masses and a realistic thermohaline circulation, although with more variability than the restoring run. Annual average production of Levantine Intermediate Water (LIW) is 1.3 ± 0.3 Sv on a core density of σ? = 29.05. A major component of variation is on a timescale of 2?3 yr and is correlated with changes in surface salinity in the Levantine by 0.1 psu, which are in turn related to a variable path for the modified Atlantic water in the eastern basin. Smaller variations in production of deep waters in the Adriatic and Western Mediterranean are also found to be significantly correlated with the LIW production at lags of 2 and 6 yr respectively.