A DESCRIPTION OF COADS SURFACE METEOROLOGICAL FIELDS AND THE IMPLIED SVERDRUP TRANSPORTS FOR THE ATLANTIC-OCEAN FROM 30-DEGREES-S TO 60-DEGREES-N

Using COADS data spanning 1947-1988, we describe the regional nature o f the Atlantic Ocean wind-driven circulation between 30-degrees-S and 60-degrees-N and its annual and interannual variability. The Sverdrup streamfunction defines the circulation gyres. Our focus is on three ce ntral gyres: the Northern Hemisphere anticyclonic subtropical gyre, th e cyclonic tropical gyre just north of the equator, and the clockwise equatorial gyre straddling the equator. This rendition of the Sverdrup streamfunction, computed with constant drag coefficient and air densi ty, compares favorably with that from other climatologies. In the Stra its of Florida, analyses suggest that differences between the annual c ycle in Sverdrup transport and observations may be due to regional win ds farther north. In the tropical gyre, the Sverdrup circulation argue s against a continuous western boundary current transporting water fro m the equatorial region into the Caribbean in boreal winter, bringing to question the mechanisms for the known interhemisphere and intergyre exchanges of heat and mass. A conceptual model is proposed involving two stages. First, the western boundary current closing the clockwise equatorial gyre is instrumental in storing heat and mass between the N orth Equatorial Countercurrent ridge and the North Equatorial Current trough in boreal summer. Transport farther north, across the tropical gyre and into the subtropical gyre, in boreal winter is then accomplis hed by Ekman transport, as the seasonal change in wind-stress torque d eepens the thermocline, thus allowing for vortex stretching and northw ard Sverdrup transport over the region of warmest waters. Once in the subtropical gyre, the Ekman transport continues to be northward despit e the fact that the Sverdrup transport reverses to be southward. Annua l and interannual variability is addressed by examining the spectrum o f curl and its regional distribution. Outside the tropics and the Sarg asso Sea, interannual exceeds annual variability by at least a factor of 1.5. A pentadal analysis in the subtropical gyre indicates that win d-stress curl was not a major factor in the density structure differen ces reported between 1955-1959 and 1970-1974; hence, these require oth er explanations.