Abstract:
Concurrent measurements of water temperature microprofiles were taken at the air-water interface of a stratified lake, while moderate wind speeds ranging from 0.8 to 8.2 m/s were present above the lake surface. Daytime measurements have shown that water surface temperatures exhibit the cool skin effect, which in turn cools the surface of the lake and induces natural convection. The velocity scale of natural convection influences both the thickness of the diffusive thermal sublayer and the net heat flux at the interface. The thickness of the diffusive thermal sublayer varied between 0.7 and 3.6 millimeters. By using the temperature microprofiles and proposed parameterization of skin-to-bulk temperatures, it becomes possible to scale temperature microprofiles over the diffusive thermal sublayer thickness. The suggested parameterizations enable the estimation of the thickness of the diffusive thermal sublayer and the temperature difference between the surface and the bulk fluid in the presence of natural convection. The surface temperatures of lake water play a vital role in linking different environments, such as atmosphere, land, and algal habitats. Harmful algal blooms occur when naturally existing algae or cyanobacteria grow excessively, causing damage to the environment, animals, and humans worldwide. Our goal with this presentation is to demonstrate how fluid motion affects the growth and heterogeneity of harmful algae in lakes. We will illustrate the application of drones and spectral cameras in quantifying the amount of harmful algal biomass present in lakes.
