A revised formulation of ocean wave dissipation and its model impact

TitleA revised formulation of ocean wave dissipation and its model impact
Publication TypeMiscellaneous
Year of Publication2007
AuthorsBidlot, J-R, Janssen, P, Abdalla, S
Secondary TitleTechnical Memorandum
Number509
Abstract

The wave model dissipation source function in the ECMWF operational model has been reformulated in terms of mean wave parameters that give more emphasis on the high-frequency part of the wave spectrum resulting in a more realistic interaction between windsea and swell. This has allowed the relaxation of the prognostic frequency range over which the model equations are integrated. These modifications resulted in improved analyses of wave model parameters, particularly those that are more sensitive to the high frequency part of the spectrum (e.g. mean wave period). Following pre-operational testing, the changes were implemented in the operational model in April 2005. Long term statistics confirm the benefit of the revised formulations.