Özsoy is Professor of Physical Oceanography. In 1977–1978, he served as Staff Engineer at Tetra Tech Inc., Jacksonville, FL, USA; since 1978 he has been Professor of physical oceanography at Institute of Marine Sciences, METU, Erdemli, Mersin, Turkey; following an academic and research career as Visiting Scientist at IMGA-CNR, Modena, Italy in 1989; Visiting Professor, UNESCO and Fulbright Fellow at Division of Applied Science at Harvard University, Cambridge, MA, USA in 1989–1990; Visiting Scientist at University of Bologna, Bologna, Italy in 2014–2015; Invited Professor at EIES-ITU in İstanbul, Turkey in 2015–2017; an Emeritus living in Ankara, Turkey after 2017.Research interests and contributions include ocean modeling of the Levantine Basin of the Eastern Mediterranean, Black Sea, Caspian Sea, Turkish Straits System; circulation, cascading flows across shelf seas of the Eastern Mediterranean and Black Sea; dynamics, transport modelingof Bosphorus / Dardanelles Straits of the Turkish Straits System; quasi-geostrophic dynamics of seas with islands; coupled hydrodynamics-ecosystem modeling; double diffusive convection, boundary and interior mixing; operational oceanographic and atmospheric observing and forecasting systems; atmospheric transport of aerosol dust; oceanographic use of tracers for analyses of deep water renewal and transport; transport at tidal inlets; modeling of Eastern Mediterranean tsunami; climate variability and climate change /in the Seas of the Old World; history of oceanography - 17th century work of Marsili in the Bosphorus.Contributions in projects include major Consortia of the Physical Oceanography of the Eastern Mediterranean (POEM); Black Sea (CoMSBlack); EU Copernicus Projects on Ventilation of the Black Sea and Aral Sea (ARAL-KUM); - European Integrated Projects  MFSTEP, MERSEA, ECOOP, IASON, SESAME, MyOcean, MyOcean2, MyOcean FO, PERSEUS, Copernicus Marine Environment Monitoring Service (CMEMS), NATO Projects TU-Fisheries, TU-Black Sea, TU-Black Sea ODBMS, MACE-Caspian Sea; IAEA Coordinated Research Project Environmental Pollution of the Black Sea; TÜBİTAK Public Research Group project on observing and forecasting systems MOMA; other local research projects (Akkuyu NPP Tsunami, Shelf projects, SEKA, İskenderun, İSKİ, Turkish Straits System İTÜVSAM / TURBO).

• Stratified / rotating fluid dynamics of the atmosphere.– Ocean.- Development of the equations.- Basic and perturbed states.- Quasi-Geostrophic theory.- Internal waves.- Two-layer model.- Convection.- Boundary layers in stratified fluids.- Jets and buoyant plumes.- Diffusion and transport processes.- Equations for diffusion processes.- Simple models of turbulent diffusion and transport.- Shear flow dispersion.- Transport of suspended sediments.- Estuarine transport.- Simple ecosystem models.- Introduction.- Dynamics of ecosystems.- Ecosystem models.