Assimilation of sea-level anomalies and Argo data into HYCOM and its impact on the 24 hour forecasts in the western tropical and South Atlantic

Argo and along-track sea-level anomaly (SLA) data from satellites were assimilated into the Hybrid Coordinate Ocean Model in the western tropical and South Atlantic Ocean. An optimal interpolation method was employed in the assimilation, and the Cooper and Haines scheme projected the altimetry information into the subsurface. The run with assimilation of SLA and Argo data reduced the root mean square deviation of the 24 h forecasts of SLA, sea surface temperature, and subsurface temperature and salinity by 21.4%, 11.5%, 28.1%, and 15.8%, respectively, with respect to the control run without assimilation. Important improvements were also observed in the circulation.