Combined Aerial and Shipboard Upwelling Study in the Benguela Current

Abstract

UPWELLING of cold, low salinity water occurs seasonally off the south and west coasts of southern Africa^1–3, and is part of the Benguela current system which extends from the Cape of Good Hope to Cape Frio, 1,000 miles to the north. As part of a detailed study programme of coastal upwelling, a survey was undertaken off the Cape Peninsula between November 18 and 29, 1968. Three methods were used in this survey: daily near-synoptic surface temperature charts were produced with a continuously recording airborne radiation thermometer (ART) on four lines parallel to the coast; a grid of fixed stations (see Fig. 1a) was covered four times by RS Sardinops; and a drogue, lowered in a recently upwelled water mass, was followed for 72 h. Comprehensive biological, chemical and physical measurements were carried out on board ship.