Effects of spatial wind variability on currents and temperature dynamics of shallow lakes

The wind above lakes can vary spatially due to their large surface and because an internal boundary layer (IBL) may develop, but its effect is often neglected. We aim to find changes in the temperature dynamics caused by the spatially varying wind using observations and a validated 3D lake model. We apply different wind forcings: interpolated with IBL considered, interpolated without IBL, and a vector-averaged uniform distribution to examine the modeled temperature structures. We found that considering the IBL is necessary for the wind forcing to accurately model not only the flow conditions and circulation patterns, but also the temperature dynamics. Depth-averaged and surface temperatures are affected through the turbulent heat fluxes, while the stratification is impacted through the mixing due to the wind variability. The predicted temperature difference along the fetch could be 100% higher when we apply simpler wind models without considering the IBL.