Zonal intermediate currents in the equatorial Atlantic Ocean

[1] Acoustic float data collected near 800 m depth, are used to map zonal mean currents within the Antarctic Intermediate Water (AAIW) tongue in the equatorial Atlantic. Alternating zonal jets of 2 degrees latitudinal width are revealed between 6 degrees S and 6 degrees N. Displacements from profiling floats drifting near 1000 m depth, also reveal similar zonal jets at the base of the AAIW layer. The strongest jets (15 cm s(-1) peak) are found at 4 degrees S, 2 degrees S, 0 degrees, 2 degrees N and 4 degrees N. They are coherent longitudinally over order of 3000 km and, poleward of 1 degrees S and 1 degrees N, generally coherent vertically between 800 m and 1000 m. Large seasonal fluctuations exist at both levels: within 1 degrees of equator, AAIW at 800 m flows westward (8 cm s(-1) mean) in boreal summer and fall but eastward (3 cm s(-1) mean) in winter, whereas the flow at 1000 m is eastward in late fall and winter.