The Jefferson Project: Large-eddy simulations of a watershed

Abstract:

The Jefferson Project is a new endeavor at Lake George, NY by IBM Research, Rensselaer Polytechnic Institute (RPI) and The Fund for Lake George. Lake George is an oligotrophic lake - one of low nutrients - and a 30-year study recently published by RPI’s Darrin Fresh Water Institute highlighted the renowned water quality is declining from the injection of salt (from runoff), algae, and invasive species. In response, the Jefferson Project is developing a system to provide extensive data on relevant physical, chemical and biological parameters that drive ecosystem function. The system will be capable of real-time observations and interactive modeling of the atmosphere, watershed hydrology, lake circulation and food web dynamics.

In this presentation, we describe the development of the operational forecast system used to simulate the atmosphere in the model stack, Deep Thunder^TM (a configuration of the ARW-WRF model). The model performs 48-hr forecasts twice daily in a nested configuration, and in this study we present results from ongoing tests where the innermost domains are dx = 333-m and 111-m. We discuss the model’s ability to simulate boundary layer processes, lake surface conditions (an input into the lake model), and precipitation (an input into the hydrology model) during different weather regimes, and the challenges of data assimilation and validation at this scale. We also explore the potential for additional nests over select regions of the watershed to better capture turbulent boundary layer motions.