From oceans to lakes, hurricane Sandy reveals clear improvements in wave forecasts

As hurricane Sandy crashed onto the U.S. East coast on October 29, the Great Lakes saw some near-record high sea states, with wave heights up to 6.6 m in southern Lake Michigan. These were very well captured by the new wave modelling system developped in partnership between Ifremer and the U.S. weather service (NOAA/NCEP).

 This new model draws from the IOWAGA project led by F. Ardhuin at Ifremer, including results from the Ph.D. work of Jean-François Filipot. The main novelty of this work is the combination of a new theory of swell dissipation, and a new method for estimating the energy dissipated in breaking waves. For the first time, an operational wave model actually estimates the number of breaking waves and uses this information to reduce the energy of the waves.

This new application to the Great Lakes follows the operational implementation of the same model to the global ocean, in May 2012, following a very similar update at Meteo-France in 2010. This new understanding of wave evolution was made possible by the analysis of satellite data and an international collaborative effort funded by the U.S. Navy and involving other partners from Australia and the Netherlands.

Future evolutions are now being developped to further improve these estimations of swell dissipation and also the estimation of the ocean surface roughness which is very important for the forecasting of storm surges. These future improvements will use novel data and analysis methods developped in the IOWAGA project, and a strong partnership with Meteo-France and the European Center for Medium range Weather Forecasting in order to adjust the effects of waves on winds and storm surges.

 This new model draws from the IOWAGA project led by F. Ardhuin at Ifremer, including results from the Ph.D. work of Jean-François Filipot. The new model particularly.