Model Oceanographic System for the monitoring of Kalloni Gulf (Model Kalloni)

Aim

The project "Kalloni Model" aims to develop a model system for studying the circulation and functioning of Gulfs typical to the Greek coasts. The project's target is to set the basis so that, in combination with other research initiatives of the Laboratory of Physical and Chemical Oceanography, and the Department of Marine Sciences in general, the Kalloni Gulf will become the best managed coastal system in Greece.

Methodology Innovations

Specific innovations employed within the "Kalloni Model" project are the following:

• Utilization of a submarine telephone cable -for the first time in the Mediterranean- to assess as well as continuously monitor water exchanges between the Gulf and the open Sea.

• Inclusion of high-frequency processes (such as tidal forcing and wave-current interactions) in the numerical simulations of the Gulf's circulation and functioning.

• Calibration of the submarine-cable method using towed and moored Acoustic Doppler Current Profiler for the estimation of the exchanges, as well as via closing the volume budget of the basin.

• Monitoring of the circulation using drifters to compare with the numerically simulated fields.

Implementation

Since mid-May 2019, extended field campaigns have been conducted in and out of Kalloni Bay, including:

• Oceanographic transects along the Strait to study the dynamics of exchange and mixing between the Bay and open Sea waters.

• Transects across the Strait to quantify the water exchange and thus calibrate the submarine telephone cable measurements.

• Wave measurements at two selected locations in the Bay.

• Three oceanographic moorings (carrying Texas A&M University instruments) deployed in the Bay, providing the variability of currents and temperature n the Gulf.

• Meteorological and solar and infrared radiation measurements.

• Concurrently, the voltage difference between the coasts of Nyphida and Apotheka is recorded, in order to be converted to water volume flux values.

Sample of Preliminary results

Figure1. Distribution of temperature, salinity, density, chl-α and turbudity along the Strait
in May 2019.

The distribution of verious hydrographic parameters on a transect along the Strait is shown in fig.1, revealing that during that period the basin behaves as a dilution basin, and that intensive mixing takes place at the southern end of the Strait (where the bethymetric through narrows and the flow accelerates).

Long-term planning

The project "Kalloni Model", albeit especially ambitious byitself, is part of a larger-scale plan of the Department of Marine Sciences to make Kalloni Gulf a model for Coastal Management and the focus of Coastal and Marine Research and Education.

Acknowledgements

This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning 2014-2020» in the context of the project “Model Oceanographic System for the monitoring of Kalloni Gulf (Model Kalloni)” (MIS 5004239). We are also grateful to the management and the personnel of the COSMOTE Group of Companies for their support fothe project.