UBC Theses and Dissertations
A 1D ocean mixing model of the Strait of Georgia : ecological responses to physical forcing Collins, A. Kathleen
A coupled biophysical model of the Strait of Georgia, British Columbia, Canada has been developed and successfully predicts the timing of the spring phytoplankton bloom. The physical model is a one dimensional vertical mixing model that is forced with hourly winds, cloud fraction, air temperature, and humidity, daily hydrographic data, and initial profiles of temperature, salinity, and fluorescence. The physical model uses a K Profile Parameterization of the boundary layer, and includes local parameterizations for albedo, cloud filtering, light attenuation, heat and freshwater fluxes. The Fraser River is used to parameterize freshwater flux, horizontal advection, and upwelling. The biological model includes one phytoplankton class (microphytoplankton) and one nutrient source (nitrate). The coupled biophysical model was tested to determine what physical factors are controlling the arrival of the spring bloom. Wind was found to control the timing of the bloom arrival, with strong winds delaying the bloom and weak winds causing the bloom to arrive earlier. Solar irradiance had a small effect on the arrival time and freshwater input (primarily Fraser River discharge) was insignificant to the arrival time of the bloom.
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