The Benguela Current Experiment

Principal Investigators

Silvia L. Garzoli (NOAA-AOML)
Philip L. Richardon (WHOI)

Collaborators

David Fratantoni (WHOI)
Christopher Duncombe Rae (SFRI)
Gustavo Goni (NOAA-AOML)
Andreas Roubicek (NOAA)

Motivation

The main objective of this program is to study the pathways, velocity, transport and variability of the Benguela Current and its extension with emphasis on tracking floats in the intermediate water. It is expected that the results of this program will make a significant contribution towards the understanding of inter-ocean (Indian to Atlantic) and inter-basin (South and North Atlantic) exchange of intermediate water, and its role in heat and mass exchanges. This program is a component of KAPEX (Cape of Good Hope Experiment), a joint US, German, and South African experiment.

During KAPEX over 100 RAFOS floats and nine sound sources will measure ocean trajectories for the first time in the Agulhas Current, in its rings which enter the South Atlantic, and in the Benguela Current and its extension, which is the source of water moving northward through the Atlantic in the meridional overturning circulation cell. In addition CTD, XBT and velocity profiles will document the water mass and velocity structure of the Benguela Current, its extension and several Agulhas rings.

Progress

In March, 1997 a German cruise on the Polarstern led by W. Zenk and O. Boebel launched 35 RAFOS floats and five sound sources (including one of the US sources near 20S 4E) in the general area west and southwest of Cape Town. During August 1997 a US cruise on the R/V S. Johnson led by T. Rossby launched three sound sources east and southeast of Cape Town. Fifty RAFOS floats will be launched in the Agulhas Current starting in November 1997. During the Benguela Current Experiment cruise on the R/V S. Johnson in September 32 RAFOS floats and two sound sources in the general area west and northwest of Cape Town 1997 were launched. (See Figure 1, below)

Figure 1: Benguela Current Experiment cruise track. R/V Seward Johnson, Sept. 4 - Oct. 1, 1997.

Results