Σαράντης Σοφιανός, επίκουρος καθηγητής, τμήμα φυσικής, ΕΚΠΑ
The goal of this work, is to investigate the effects of surface water turbidity in the physical characteristics and dynamical processes of the Mediterranean Sea, using an ocean numerical model. The spatial resolution of the model is set to 1/12° × 1/12°, being able to resolve the Rossby radius of deformation in the region. In this study we carried out two experiments, where in the first one, the water turbidity is minimum and is considered for clear waters in the ocean, i.e. water type I according to Jerlov, with attenuation depth of 23 m and in the second experiment is considered maximum in the ocean, i.e. water type III according to Jerlov, with attenuation depth of 7.9 m. Results show that increased surface water turbidity has a measurable impact in the Mediterranean Sea dynamics. For instance, the mixed layer depth decreases by about 11 m at an annual basis (decrease of 27%) and by about 40 m (decrease of 44%) during winter. The upper ocean layer of 0-8 m, corresponding also to the attenuation depth for type III waters, becomes colder by 0.23 ºC, whilst the whole Mediterranean basin becomes colder by 0.84 ºC and the heat loss to the atmosphere is decreased by 1 W/m2. Stratification is intensified for the highly turbid experiment, leading to decreased vertical mixing (vertical eddy viscosity decreases by 60% during winter) and increased mean kinetic energy. Inflow of Atlantic waters though the Gibraltar strait increases by 0.1 Sv (increase of ~12%).
Turbidity, Mediterranean, physics, ocean, oceanography