Satellite observation of ocean colour off the South African West Coast

Abstract

The Coastal Zone Colour Scanner (CZCS) on board of the Nimbus-7 satellite measures ocean radiance at different wavelengths in order to map phytoplankton pigment distributions and sediment distributions as well as temperature patterns in the coastal zone. A series of optical and biological measurements were carried out along the Cape West Coast to determine the relationship between ocean colour and phytoplankton pigment concentration. This paper presents a brief description of the algorithm used to determine phytoplankton pigment from satellite data, which is then compared with sea data collected during February 1979 off the West Coast. Results indicate that the pigments can be determined with a accuracy of factor 2, which compares favourably with the results obtained by other investigators. It appears that this new method of pigment determination on a global scale will provide an important tool in the study of upwelling processes and in a more efficient management of fish resources.