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.
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.
