Analysis of Wave Fields During Ship Accidents in the North-Western Mediterranean

The occurrence of extreme waves in real sea conditions and their generation mechanisms are key elements in regional forecasts to improve the safety of navigation, especially in those severe conditions where large ships depart and adapt their routes based only on average wave parameters, as the significant wave height. In the present work we have analyzed a series of accidents occurred in the North-Western Mediterranean Sea to large passengers and cargo ships, involving injured people, damages and partial loss of cargo. We have performed phase-resolving numerical simulations based on the Higher Order Spectral Method (HOS), initialized with WaveWatch III (WWIII) directional wave spectra, to analyze in details the sea conditions during the accidents from a statistical point of view. For each case study we have repeated several 3-dimensional realizations to ensure statistical accuracy, and we have tested also the impact of the atmospherical forcing in the WWIII model as well as the nonlinear source term parametrization. The statistical analysis is based on the evaluation of statistical moments as skewness and kurtosis of the free surface elevation, which are typical indicators of nonlinearities and extreme waves, and on the reconstruction of crests distributions, from space-time analysis. Finally, we have focused the attention on spectral shapes similarities among the different case studies and on its possible effect on rogue waves formation.