Effect of Wind Reduction Factors on Forecasting Circulation in an Estuary

Extreme events such as offshore hurricanes, storm surge and wind-driven waves have potentially large impacts on coastal ecosystems and can cause long term damage to coastal estuaries. ADvanced CIRCulation (ADCIRC) hydrodynamic model coupled with Simulating WAves Nearshore (SWAN) is applied to study wind-driven circulation in Indian River Lagoon, a micro-tidal long and narrow estuary extended along the central east coast of Florida, as part of a NOAA funded CSTAR project. Due to the unique geometry of the IRL, significant wave height and water elevation are sensitive to the meteorological forcing. The sensitivity of the model to two methods of down-scaling the winds are investigated: one in which high resolution downscaled winds are computed numerically by the WRF model, and a second more simple method where the NLCD surface roughness's are used to scale the wind stress to the model resolution. The wind setup differences between these two models are compared and the performance of the ADCIRC model is assessed. Results obtained from ADCIRC are validated against available elevation station data.