Assimilation of radar altimeter data in numerical wave models: an impact study in two different wave climate regions

G. Emmanouil , G. Galanis (1) , G. Kallos , L. A. Breivik (2) , H. Heiberg (2) , M. Reistad (2)

1 Naval Academy of Greece
2 MET - Norwegian Meteorological Institute [Oslo]

An operational assimilation system incorporating significant wave height observations in high resolution numerical wave models is studied and evaluated. In particular, altimeter satellite data provided by the European Space Agency (ESA-ENVISAT) are assimilated in the wave model WAM which operates in two different wave climate areas: the Mediterranean Sea and the Indian Ocean. The first is a wind-sea dominated area while in the second, swell is the principal part of the sea state, a fact that seriously affects the performance of the assimilation scheme. A detailed study of the different impact is presented and the resulting forecasts are evaluated against available buoy and satellite observations. The corresponding results show a considerable improvement in wave forecasting for the Indian Ocean while in the Mediterranean Sea the assimilation impact is restricted to isolated areas.

Domaines: Océan, Atmosphère; Sciences de la Terre

G. Emmanouil, G. Galanis, G. Kallos, L. A. Breivik, H. Heiberg, et al.. Assimilation of radar altimeter data in numerical wave models: an impact study in two different wave climate regions. Annales Geophysicae, 2007, 25 (3), pp.581-595. ⟨hal-00318287⟩