Abstract:

We calculate the monthly components of the Mediterranean Sea heat budget, namely the net shortwave, net longwave, latent, sensible heat fluxes, and heat storage change, for years 1984-2000. The radiative components of the seasonal heat budget are derived by a radiation transfer model, while in most other studies bulk formulae are used. A variety of data are required to run the model, among which are cloud data from International Satellite Cloud Climatology Project (ISCCP) D2 data set, aerosol data from Global Aerosol Data Set (GADS), temperature and humidity from National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and European Centre for Medium-range Weather Forecasts (ECMWF) Re-Analysis (ERA-40), and oceanographical data from Mediterranean Data Archaeology and Rescue (MEDAR) MEDATLAS database and the World Ocean Atlas 2001. We compare two methods for the estimation of the monthly latent heat flux and evaporation: the bulk aerodynamic and the heat balance. The average annual evaporation rate for the Mediterranean Sea, based on the heat balance method, is estimated at 1500 ± 190 mm yr^-1. The bulk aerodynamic method produces estimates of the annual evaporation rate in the range 1060-1280 mm yr^-1, depending on the source of the input data. The analysis of the heat content shows that the solar heat absorbed by the sea during summer is redistributed to winter evaporation via heat storage by the sea. Thus the peak evaporation occurs in winter and is mainly driven by energy released (100-150 Wm^-2) from sea heat storage.

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