Wave-current interactions in the northwest Atlantic Ocean during Hurricane Arthur

Wave-current interactions (WCIs) are important over coastal and shelf waters during extreme weather conditions. In this study, an advanced coupled circulation-wave modelling system is used to investigate WCIs during Hurricane Arthur (2014), with an emphasis on effects of Langmuir turbulence (LT) and wave breaking (WB). Different from previous studies on WCIs, WCIs are examined in shallow and intermediate water depths in addition to deep water. The proximity of the storm track to the coastline also limits the fetch. This further increases the asymmetric distributions of significant wave heights, near-inertial currents and vertical mixing. Our results show that both LT and WB affect the storm-induced changes to the temperature/salinity and circulation in the upper ocean. LT enhanced the surface cold wake over the Mid-Atlantic Bight by further cooling of up to 0.5 ° C. Over the region between the Gulf of Maine and Scotian Shelf, LT-enhanced cooling is also prominent. In the Gulf of St. Lawrence, the LT-enhanced cooling is a result of the cumulative effect of other storms during the model spin-up prior to Arthur. WB-driven acceleration increases the storm-induced horizontal advection in the Mid-Atlantic Bight. Over the Gulf of Maine and Scotian Shelf, the WB contributions to momentum and cooling are larger to the right of the storm track. In the southern part of the Gulf of St. Lawrence, WB increases the surface cooling. Conservative Stokes drift effects and the wave-induced bottom boundary layer have a much smaller impact than LT and WB.