Some Parametric and Structural Simulations With a three-Dimensional Ecosystem Model of Nitrogen Cycling in the North Atlantic Euphotic Zone
The Joint Global Ocean Flux Study (JGOFS) is a major international scientific program with the aim of understanding the role of biological processes in the ocean carbon cycle (the “biological pump”). One of the major aims of this project is to be able to model the effect of the biological pump on carbon dioxide drawdown from the atmosphere and to determine its geographical and seasonal variation and what part this pump may play in climatic change (Fasham et al., 1991). This is an ambitious undertaking and it will be some years before we can judge its success. The first requirement is to develop a model of biological production that possesses some geographical generality; the assumption being that the underlying structure of the marine ecosystem is similar throughout the world ocean but that different physical forcing scenarios give rise to different seasonal cycles and the relative concentrations of the individual components of the food web. One of the problems with developing such a generic model is that even simple biological models contain a large number of parameters which are often difficult to measure and, in any event, represent some average value over the diverse species that make up the phytoplankton, Zooplankton, and bacterial populations. It is still an open question whether such a model can be produced but in the meantime we should investigate candidate models for their agreement with observations and also determine the senstitvity of the models to the parameter set.
KeywordsWind Stress Spring Bloom Deep Chlorophyll Maximum Biological Pump Photic Layer
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