On the importance of the choice of wind stress forcing to the modeling of the Mediterranean Sea circulation

Abstract

A 1/4° degree ocean general circulation model is used to examine the role that four different wind stress climatologies play on the circulation of the Mediterranean. The wind stress climatologies examined are those derived from numerical weather prediction models (National Meteorological Center (NMC) and European Centre for Medium‐Range Weather Forecasts (ECMWF)) and one based on observations (Southampton Oceanography Centre (SOC)). Significant differences exist between the wind climatologies over the Mediterranean and in the response of an ocean general circulation model forced by the different climatologies. Excessive coastal upwelling/downwelling is found to be associated with the extreme zonal nature of one of the climatologies. Surface circulation differences include the position and penetration of the Mid‐Mediterranean Jet into the Levantine, the Ionian, and the Tyrrhenian circulations. Significant differences exist in the pathways for dispersal of Levantine Intermediate Water. Under the SOC forcing, there is a reduction in Eastern Mediterranean Deep Water formation in the Southern Adriatic, compensated by the production of intermediate or deep water in the Aegean. The ECMWF climatology is found to be associated with much more cyclonic doming in the Gulf of Lions, leading to better formation of Western Mediterranean Deep Water.