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Disclaimer: The Physical Oceanography Research Group (PO-Res. Grp) makes every effort to ensure that information contained in these pages is accurate and up to date. However, the PO-Res. Grp accepts no liability and/or responsibility for the reliance placed by the users of these pages on the information contained in these pages or any other information accessed via this web page. The information provided in these pages is provided on an "as is" basis and no warranties of any kind are issued whether expressly or implied by the PO-Res. Grp on the information provided.
CALYPSO HF Radar Map of Sea Surface Currents
This web service interface was developed and is maintained by
the Physical Oceanography Research Group.
CALYPSO HF radar map


The map shows real time hourly averaged sea surface currents in the stretch of sea between Malta and Sicily and off the southern coast of the Maltese Islands. This data is generated from measurements made by seven HF radars that make up the CALYPSO network.

HF radars transmit a vertically polarised signal which propagates onto the water in a radial path away from the mast reaching well beyond the line-of-sight. When the radar signal hits ocean waves, it is scattered in many directions with the sea surface acting like a large diffraction grating. By Bragg’s principle, the radar signal produces an echo returning directly to its source only when the signal scatters off a sea wave with a wavelength that is exactly half the wavelength of the transmitted radio signal, and when the sea wave is travelling in a radial path either directly away from or towards the radar. This reflected signal is detected by the radar and processed to calculate the radial velocity component of the surface current.

By installing more than one radar at different locations with an overlapping beam pattern, the same patch of water can be viewed from different angles, and the surface current radial velocity components can be summed to determine the total surface current velocity vector. This data measured simultaneously at different points can be combined to produce hourly maps of current vectors on a regular grid. This data can be represented in the form of arrows showing the size and direction of the sea currents as in the above map.

The CALYPSO network covers two domains, the Malta-Sicily Channel and the Southern coast of Malta. The Malta-Sicily Channel cluster of radars are installed in Licata, Marina di Ragusa and Pozzallo on the Sicilian side, and Ta’ Sopu in Gozo and Ta’ Barkat in Malta, on the Maltese side. Together these radars cover a significant area of the Channel which is subject to heavy marine traffic.

The Southern Malta cluster includes two radars, one at Ta’ Ċenċ in Gozo and another at Għar Lapsi in Malta. The sea surface current data collected here will be invaluable to learn more about this relatively unexplored area in the Mediterranean Sea.

Log in to the CALYPSO Professional Data Interface for full access to the service. Username and Password are needed and can be requested by writing to the Project Coordinator: Prof. Aldo Drago (aldo.drago@um.edu.mt)

Disclaimer: The Physical Oceanography Research Group (PO-Res. Grp) makes every effort to ensure that information contained in these pages is accurate and up to date. However, the PO-Res. Grp accepts no liability and/or responsibility for the reliance placed by the users of these pages on the information contained in these pages or any other information accessed via this web page. The information provided in these pages is provided on an "as is" basis and no warranties of any kind are issued whether expressly or implied by the PO-Res. Grp on the information provided.