MODEL OF PHYTOPLANKTON GROWTH-EFFECTS OF VERTICAL MIXING AND ADAPTATION TO LIGHT.

Abstract

The model describes growth of phytoplankton as a function of light intensity, level of adaptation, concentration of nutrients (nitrogen), temperature, grazing and respiration. The level of adaptation is a dynamic function of the past light experience of the algal cells which again depends on the light intensity at the surface and the vertical mixing. Simulation runs have been performed using a one-dimensional (vertical direction) physical model where the turbulent mixing can be specified. The effect on the onset and the dynamics of the spring bloom is discussed for typical vertical mixing profiles found along the Norwegian Coast and in the Barents Sea. The adaptation level is found to have a pronounced effect on the date for the onset of the spring bloom.