9317986 MacIntyre This research investigates the vertical circulation of phytoplankton by turbulent motions over diurnal cycles and how this circulation affects photosynthetic rates. It also investigates the relative importance of nutrient supply to the euphytic zone via diapycnal mixing and horizontal exchanges. The project comprises time-series measurements of vertical mixing and horizontal exchange coupled with estimates of photosynthetic rates and profiles of nutrient concentrations taken over the same periods. %%% This study will provide the first systematic analysis of vertical mixing in which turbulence dynamics are directly measured and related to the light environment of phytoplankton. These data, coupled with information to be gathered on the dynamics of nutrient movement, will permit proper analysis of resource-based models of primary productivity, nutrient competition, and phytoplankton succession. The results of this research will have applications in analysis of ecosystem function and health and aquatic pollution monitoring. ***
