Surface currents derived from satellite-tracked buoys off Namibia

To study the flow field off Namibia (20-30 degrees S, 10-15 degrees E), 48 satellite-tracked buoys were deployed and tracked in six bimonthly batches between July 1994 to September 1995. In situ supporting wind information was collected from a weather buoy moored off Luderitz, from coastal stations and from voluntary observing ships. Buoy drift tracks were compared with surface topography data from the TOPEX/POSEIDON satellite and satellite infrared images. Most of the buoys drifted in a northwesterly direction, the buoys deployed in the south generally moving faster and diverging more from the coast than the northern buoys. The overall maximum daily drift velocity was 72 cm s(-1), but typical speeds were 10-30 cm s(-1). In the proximity of the coast some buoys experienced transient southward sets associated with the effect of coastal trapped waves, while tracks north of 23 degrees S showed inertial oscillations. (C) 1999 Elsevier Science Ltd. All rights reserved.