CTR NATL ETUD SPATIALES,RECH GEODESIE SPATIALE GRP,SERV HYDROG & OCEANOG MARINE,F-31055 TOULOUSE,FRANCE.
Journal Of Geophysical Research-oceans (0148-0227) (Amer Geophysical Union), 1990-11 , Vol. 95 , N. C11 , P. 20267-20285
Two years of Geosat data were used to systematically investigate the mesoscale variability and spatial scales of the North Atlantic. We first calculated sea surface height variability and eddy kinetic energy. These compare well with the eddy kinetic energy obtained with surface drifters. Then the spatial scales of mesoscale variability were characterized in 10° (latitude) × 10° (longitude) areas by their wave number spectra and autocorrelation functions. Comparison with existing in situ data shows good agreement, and it is believed that the total error budget is globally below that of the oceanic signal. The wave number spectra show significant differences as a function of latitude and longitude, and these can be related to different types of forcing (instability of a mean current or fluctuating wind). Scales typically decrease from west to east and south to north. Simple proportionality with respect to the first internal Rossby radii does not apply everywhere.