Southern Ocean productivity in relation to spatial and temporal variation in the physical environment

• Published in: Journal of Geophysical Research
• Main Authors: Constable, AJ, Nicol, S, Strutton, PG
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Geophysical Union 2003
• Subjects: Earth Sciences; Oceanography; Biological Oceanography; Antarctic; Southern Ocean; Antarc*; Sea ice
• Online Access: https://doi.org/10.1029/2001JC001270; http://ecite.utas.edu.au/138636

The physical factors that have been reported to affect primary and secondaryproduction in the Southern Ocean are examined and critically reviewed. Long time seriesof physical measurements from the Southern Ocean are available and there is a theoreticalbase from which models can be constructed. In contrast, there are few large-scalemeasurements of biological parameters and a paucity of long-term biological data sets forthe Antarctic region. The absence of predictive models for the biological systems of theregion is underpinned by the absence of theoretical understanding of the variations in thephysical environment and their effects on primary, secondary, or tertiary production. Tofurther this understanding, we have examined some of the major seasonal and interannualphysical data available for the region (sea ice extent and retreat rate, wind stress, andsurface ocean circulation patterns) and have examined their relationship to spatial andtemporal variation in satellite-derived proxies of primary productivity (Sea-viewing WideField-of-view Sensor (SeaWiFS) ocean color data). The results indicate that there areregional differences in the dominant physical forcings and that simple models will fail toreplicate the observed patterns of primary production. We have also used the dynamics ofAntarctic krill in the South Atlantic as an example to develop a model and explore thevarious hypotheses that have been put forward to explain interannual variability in thisregion. Results from this model indicate that the physical system may change in ways thatcause periodic shifts in the relative importance of the factors that affect secondaryproduction. The implications for the design of future research programs areexplored.