Turbulent Mixing: Effects on Resource Supply and Primary Production in Lakes

点击翻译按钮获取中文摘要

Abstract 97-06932 MacIntyre Turbulent Mixing and Light and Nutrient Supply to Phytoplankton In lakes, physical processes that cause turbulent mixing supply resources essential for primary productivity. Partial upwelling and shoaling internal waves lead to turbulence and upward transport of deep, nutrient rich waters. The resulting nutrient fluxes have been 300% higher than those due to processes occurring offshore. Estimating the impact of vertical mixing in well-lit surface waters on primary productivity has proved elusive. Large eddies circulate phytoplankton and expose them to different intensities of irradiance. Photosynthetic rates of algae circulating in large eddies have changed by up to 80%. For lakes varying in size and stratification, the investigators will determine the location, frequency and vertical extent of mixing events and assess their contribution to nutrient fluxes, phytoplankton circulation, and lake productivity. The researchers will also develop and test models for predicting light and nutrient supply in other lakes, leading to improved predictions of primary productivity due to changing land use, weather patterns, or climate change.