A sequential assimilation scheme applied to global wave analysis and prediction

This paper examines the results of the assimilation of satellite Significant Wave Height (SWH) observations in a global wave prediction model. The model used is the third generation wave model WAM. The assimilation is carried out using a sequential (single time level) scheme. Each assimilation step is split into two parts. The analysed SWH field is built by Optimal Interpolation, and the analysed spectrum is successively derived from it and from the first guess spectrum. The period used in the study is February 1992, and the altimeter data have been provided by the ERS-1 satellite. The results show positive effects of the assimilation on both wave analysis and forecast.