Tropical Atlantic wind field variations during Sequal Preliminary results

Abstract

The Sequal (Seasonal Response of the Equatorial Atlantic) program has the objective to model correctly the dominant physical processes producing the seasonal redistribution of heat, mass, and salt in the upper ocean. The efforts of Sequal are greatly enhanced by the Focal (Francais Ocean et Climat dans l'Atlantique Equatorial) program. A knowledge of fields of wind stress over the tropical Atlantic is needed for the achievement of the Sequal objectives. The Sequal program makes use of the Fleet Numerical Oceanography Central (FNOC) 'Nogaps' wind fields as a first-guess field which will subsequently be modified. Nogaps is a global weather prediction model consisting of independent global wind and mass analysis submodels. The present investigation is concerned with some preliminary comparisons between Nogaps predictions and surface observations, taking into account monthly mean Nogaps fields and monthly means from a century-long ship report-based climatology.