QUANTIFICATION OF SOUTHERN OCEAN PHYTOPLANKTON BIOMASS AND PRIMARY PRODUCTIVITY VIA SATELLITE OBSERVATIONS AND BIOGEOCHEMICAL MODELS

This paper reviews Southern Ocean primary productivity within the framework of satellite remote sensing and the development of food-web models. The satellite ocean colour (chlorophyll) data record is described, from the Coastal Zone Colour Scanner (CZCS) in the late 1970s through to the Ocean Colour and Temperature Scanner (OCTS), the Sea-viewing, Wide Field of view Sensor (SeaWiFS), the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Medium Resolution Imaging Spectrometer (MERIS). The characteristics of these data and limitations, such as cloud cover and high solar zenith angle, are discussed with regard to their use in the Southern Ocean. A brief history of algorithms linking ocean colour to primary productivity is presented, focusing on the vertically generalised production model (VGPM) and more recent regional approaches. Using monthly climatologies of SeaWiFS chlorophyll, a phenology of phytoplankton blooms is presented for the major provinces surrounding Antarctica. Some of the published information regarding phytoplankton species composition and succession is summarised. A review of ecosystem and biogeochemical models for the Southern Ocean is presented, with a focus on those models that have been validated using satellite ocean colour data.