Monitoring sea surface currents in the Northern Adriatic Sea with HF radars
The Oceanography Department, Istituto Nazionale di Oceanografia e Geofisica Sperimentale - OGS - in Trieste, and the Institute for Marine Sciences, Consiglio Nazionale delle Ricerche - CNR ISMAR, in Venice, have a long tradition with high-frequency coastal radars for current monitoring.
The first HF radar deployment started in 1995 in the Ancona area. For the period 2001 - 2006 attention was focused on the coastal area if front of the Lagoon of Venice.
For the period 2007 - 2008, thanks to international cooperation programs with the Republic of Croatia, sponsored by the European Union, a new project will monitor the evolution of sea surface currents in the Northern Adriatic Sea, along the Istrian peninsula and the Italian coastline, in the Friuli-Venezia Giulia and Veneto area.
NASCUM project radar positioning
The Network
The monitoring network consists of four measurement sites: Rt Zub and Savudrjia in Croatia, Bibione (Punta Tagliamento) and Venezia (Punta Sabbioni) in Italy. Each antenna, the electronic and the computer are installed on top of lighthouses, because of their proximity to the ocean.
The first HF radar (Rt Zub) was installed in the first week of July 2007, while the second site was installed at Savudrjia in August 2007. The third site was installed in September 2007 on top of the Bibione-Punta Tagliamento lighthouse, and will be operational soon. The fourth site will be installed on top of the Punta Sabbion lighthouse, and will be operational by January 2008. Each antenna, in the actual configuration, is set-up with 1.5 km spatial resolution and 5° angular resolution. For each site, the maximum operational range reaches 46 km. A current vector is then estimated on a regular grid with 2-km spacing, when independent measurements from at lest two sites are available. For each grid point, a 3-km search radius is used in the vector computation.
Current maps for the Istrian coast are now available, showing the structure of sea-surface currents and their temporal evolution in this region. Each current map was obtained combining the informations recorded by the two sites Rt Zub and Savudrjia. Arrow lengths and size indicate direction and magnitude of water flow at the surface. Colors correspond to current speeds in cm/s, the legend is shown at right.