Storm-Induced Circulation in Lunenburg Bay of Nova Scotia: Observations and Numerical Simulations

Abstract

An extreme weather event (Hurricane Juan) made landfall in Nova Scotia, Canada, in September 2003. The storm produced an ?70-cm storm surge and ?40 cm s?1 coastal currents in Lunenburg Bay, registered by a coastal observing system. A fine-resolution (60 m) coastal circulation model is used to examine the response of Lunenburg Bay to Hurricane Juan. The model is forced by local wind stress at the sea surface, and tides and remotely generated waves specified at model open boundaries. The model performance is assessed in terms of ?2, the variance of the model errors normalized by the observed variance. The model reproduces very well the observed surface elevations with ?2 values of less than 0.05, and reasonably well the observed currents with ?2 values between 0.2 and 1.1 in the bay during Hurricane Juan. The model?data comparisons demonstrate that the coastal circulation in the bay is significantly affected by local wind associated with the storm. The model results are also used to demonstrate the importance of nonlinear dynamics in the barotropic response of the bay to the storm.