Impact of Resolution on the Representation of the Mean and Extreme Winds along Nares Strait

Abstract

Nares Strait is the long and narrow strait bounded by steep topography that connects the Arctic Ocean's Lincoln Sea to the North Atlantic's Baffin Bay. The winds that blow along the strait play an important role in modulating ice and water exports from the Arctic Ocean as well as in helping to establish the Arctic's largest and most productive polynya that forms at its southern terminus. However, its remote location has limited our knowledge of the winds along the strait. Here we use weather station data from the region as well as 3 numerical models with horizontal resolutions that vary from ˜30km to ˜2.5 km to characterize the wind field in the vicinity of the strait. The strait has a width that varies from ˜40km to ˜100 km and as such the wind field is typically ageostrophic and controlled by the pressure gradient in the along-strait direction. We show that model resolution plays a role in the representation of both the mean and extreme winds along the strait through the ability to represent this ageostrophic flow. Higher windspeeds occur in the vicinity of Smith Sound and are the result of a left-hand corner jet. Kane Basin, the widest section of the strait, is characterized by a pronounced zonal windspeed gradient that is the result of the steep topography of the upstream Washington Land peninsula.