Investigating the seasonal vertical structure of phytoplankton in shelf seas

A 1-dimensional (vertical) physical-biological coupled model is presented. The model is designed for investigations into the link between the vertical turbulent structure of a coastal or shelf sea water column, and the primar y production. The physical model employs a turbulence closure scheme to pro vide the link between local vertical stability (driven by seasonal solar he ating) and the vertical turbulent mixing (driven by tidal currents and surf ace wind stress). The biological component of the model is a simple cell qu ota, threshold limitation model, with either 1 or 2 taxa/species of phytopl ankton growing in response to light and dissolved inorganic nitrogen. The u ser has control over all model physical and biological driving parameters. Graphical screen output, suitable for basic visualisation and teaching purp oses, is generated as the model operates, and more detailed data are writte n to files for later analysis. In order to demonstrate the model's use in simple hypothesis investigation, an example of the model operation is illustrated. This focuses on the effe ct that the springs-neaps tidal cycle has on the production within the summ er sub-surface biomass maximum, illustrating the fortnightly input of new n itrogen into the thermocline and the subsequent new production. (C) 2000 El sevier Science Ltd. All rights reserved.