WAVE FORECAST PROVIDED BY THE UNIVERSITY OF ATHENS FOR THE 39^TH INTERNATIONAL AEGEAN RALLY

During the 39^th International Aegean Sailing Rally (12-22 July 2002) organized by the Hellenic Offshore Racing Club (HORC), the Ocean Physics and Modeling (OPAM) Group of the University of Athens (http://www.oc.phys.uoa.gr) will provide detailed 3-hr wave forecasts for the areas where the regatta will take place. In that way, for the first time this year, both weather forecasts, provided by the National Observatory of Athens, and wave forecasts (significant wave height and direction) will be available to the participating sailing teams. It is believed that this combined information will play an important role in the safety of the regatta. It will also allow participating teams to better design their sailing strategy.

The wave forecasts will be available directly from the dedicated to the rally website of HORC (http://www.aegeanrally.gr) and will cover the geographical areas of the Southern Aegean Sea, the Cyclades and the Saronikos Gulf. They will consist of maps showing at each point the forecasted Significant Wave Height (see footnote) and Direction of the waves. Each and every day the numerical models will provide a new 60-hr forecast starting at 0300 UTC (20 maps at 3hr interval for each area).

Further to that, at pre-selected points, along each of the four legs of the rally, the significant wave height and direction for the forecast period will be provided in the form of time series plots.

Additional wave forecasts for the broader area of the Aegean and Mediterranean Seas will also be available at the OPAM website, http://www.oc.phys.uoa.gr .

The wave forecasts are provided through the Integrated Wave Forecast System ‘TRITON’ developed by the OPAM Group of the University of Athens. The TRITON system is based on an ensemble of the most modern and internationally recognized wave forecast models (WAM, WAVEWATCH III, SWAN). It covers areas such as the World Ocean, the Mediterranean and Black Seas, the Aegean Sea as well a number of its sub-regions, such as the N. and S. Aegean, the Ionian, the Cyclades, the Cretan Sea, the Saronikos Gulf etc. The TRITON system consists today of 14 different numerical models embedded in each other in such a way that the coarser and larger models provide boundary conditions to the intermediate size models and those in turn to the high resolution models. The model grid sizes range from 20 x 20 km for the Mediterranean to 10 x 10 km for the Aegean, 3.5 x 3.5 for the S. Aegean, 2 x 2 km for the Saronikos Gulf and finally 500 x 500 m for the Attica coasts in the Saronikos Gulf.

In all wave forecast models, with the exception of the Global Ocean one, the wind field used to force the models is taken from the Atmospheric Weather Prediction System ‘SKIRON’ developed by the Atmospheric Modeling and Weather Forecasting Group of the University of Athens (http://forecast.uoa.gr).

Note : Because of the complex form of the waves in an area and the co-existence of waves with different heights, the internationally accepted and used term for the description of the wave height is the so-called Significant Wave Height which is the average height of the highest third of the waves.