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 wa s collected from a weather buoy moored off Luderitz, from coastal stations and from voluntary observing ships. Buoy drift tracks were compared with su rface topography data from the TOPEX/POSEIDON satellite and satellite infra red images. Most of the buoys drifted in a northwesterly direction, the buo ys deployed in the south generally moving faster and diverging more from th e coast than the northern buoys. The overall maximum daily drift velocity w as 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 sho wed inertial oscillations. (C) 1999 Elsevier Science Ltd. All rights reserv ed.