A nested circulation model for the North Aegean Sea

Abstract

Abstract. A multi-nested approach has been employed for numerical simulations in the northern part of the Aegean Sea in the framework of the MFSTEP (Mediterranean Forecast System: Toward Environmental Predictions) project. The high resolution (~1.6 km) hydrodynamic model of the North Aegean Sea (NAS) has been nested within a coarser model of the Eastern Mediterranean (resolution ~3.6 km) which is also nested within a basin scale model for the Mediterranean Sea (resolution of ~7 km). The high resolution of the NAS model allows the representation of topographic details that have never been reproduced in modelling studies of the region. Such details can enhance the simulation of coastal features, but can also influence basin-scale processes, such as the pathways of waters of Black Sea origin inflowing at the Dardanelles Straits and bifurcating through island passages. We employ comparisons of the North Aegean and Eastern Mediterranean models in terms of computed flow fields and distribution of hydrodynamic properties, to evaluate the nesting procedure, the initialization requirements and the ability of a nested model to perform reliable short term simulations that employ high resolution atmospheric forcing, when initialized from a longer running coarser OGCM. We show that the topographic details of the high resolution, nested NAS model mostly affect the distribution of the Dardanelles plume, while the imposed high frequency, high resolution atmospheric forcing allows for the formation of an overall energetic flow field after a few days of spin-up period. A longer initialization procedure is suggested for the establishment of stronger currents and better developed buoyant plumes.

Modelling the cohesive sediment transport in the marine environment: the case of Thermaikos Gulf

“…Regarding the J03 run the northern riverine plume extends to the greater part of the inner gulf and the particles from Pinios spread at a significant distance from the west coast showing a southward tendency. This naturally is in accordance with the hydrodynamics of the simulation that reveal a southward buoyancy-driven coastal current that is strengthened by strong northerly winds during the last 5 days of the experiment (Kourafalou and Tsiaras, 2007).…”

“…They are the Typical One-Year Simulation (TOYS), the simulation of the period from 3 September 2001 to 31 August 2002 (S1A2) and finally the January 2003 experiment (J03) (Kourafalou and Tsiaras, 2007) concerning a run with half-daily mean input values (from the 3 to the 31 January at 00:00 and 12:00 UTC) and particle mass set to 1440 kg. Input velocity and oceanographic parameters fields for TOYS are outputs of the NAS model with perpetual year forcing (Kourafallou and Barbopoulos, 2003;Korres and Lascaratos, 2003), describing seasonal circulation patterns.…”

“…At the end of J03 the bulk deposited particles from Pinios are located to the south of the estuary and mainly close to the coast. This movement is attributed to the aforementioned buoyancy driven current along the western coast that was enhanced after 25 January 2003 by strong northern winds (Kourafalou and Tsiaras, 2007) and enabled eastward spreading of the plume and sedimentation at greater depths along the west coast.…”

Seasonal changes in growth and condition of anchovy late larvae explained with a hydrodynamic-biogeochemical model simulation

“…POM employs a bottom-following sigmacoordinate system, which is particularly suitable for coastal applications. It is a widely spread community model that has been previously implemented in the North Aegean (Kourafalou & Barbopoulos 2003, Kourafalou & Tsiaras 2007 and is part of the 'POSEI-DON' operational forecast system (Nittis et al 2006). …”

Preface "Operational oceanography in the Mediterranean Sea: the second stage of development"

“…The regional model areas were: North-Western Mediterranean (Estournel et al, 2009), the Sicily Strait (Gaberšek et al, 2007), the Adriatic Sea (Chiggiato and Oddo, 2008) and the Aegean-Levantine Sea (Sofianos et al, 2006). Two of the shelf scale models are described in this issue: the northern Aegean Sea (Kourafalou et al, 2007) and the South-eastern Levantine Sea (Zodiatis et al, 2008).…”