Supervisors info:
Σοφιανός Σαράντης (Επίκουρος Καθηγητής, Τμήμα Φυσικής, Ε.Κ.Π.Α.)
Φλόκα Έλενα (Αναπληρώτρια Καθηγήτρια, Τμήμα Φυσικής, Ε.Κ.Π.Α.)
Παπαδόπουλος Βασίλης (Ε.Λ.Ε. Β’, ΕΛ.ΚΕ.Θ.Ε.)
Summary:
Three oceanographic cruises, which were conducted in the Red Sea basin in August 2001, in March 2010 and in September and October 2011, and included observations of hydrographic characteristics, meteorological data and ocean currents, gave the opportunity to explore and better understand the structure of the water masses, their hydrographic characteristics and the circulation patterns in the basin. The aim of this study is to use the hydrographic data (temperature, salinity and dissolved oxygen concentration) which were obtained from the above cruises in order to detect interannual variability in the thermohaline characteristics and the stratification in the Red Sea basin during the decade, from 2001 to 2011.
Firstly, the intrusion of Gulf of Aden Intermediate Water in the Red Sea basin during summer was studied and the velocity of the intrusion was calculated 0.12 m/s and the northern limit of the intrusion was determined at 24 °Ν. Furthermore, the Red Sea Deep Water was studied and from the data of this work the result was that the formation of deep water is episodic. The velocity of the circulation of deep water in the deep cell is 3•10-3 m/s, a velocity which is in agreement with previous studies which calculated the residue time of deep water at approximately 40 years. In addition, the mean temperature, salinity and dissolved oxygen concentration were calculated for the depths from 300 m until the maximum depth for the stations along the axis and the results showed that there is a trend of increasing temperature with a rate of 53.85∙10-4 ˚C/yr, the salinity is decreasing with a rate of -20.88∙10-4 psu/yr and the density is decreasing with a rate of -26.92∙10-4 kg/m3∙yr. The oxygen reveals a more complicated pattern as it shows both temporal and spatial changes.
In the second part of this study, the stratification in the basin of Red Sea was studied, and the result was that there is no significant interannual variability. The Rossby radius of deformation is increasing linearly from 12 km in the north to 38 km at the exit of the basin. Finally, the comparison between the velocity of long Rossby waves and the geostrophic velocity revealed the critical latitude where there is a transition from western boundary current to an intensification of the eastern boundary current. This θcr is 19°Ν.
Keywords:
Physical Oceanography, hydrographic data, Red Sea, water masses, stratification
