The formation and dissolution of the North Water Polynya (an area of open water surrounded by a sea-ice covered ocean) was examined to determine the spatial and temporal variability of the Smith Sound ice arch (a feature that prevents ice from covering the polynya). A passive microwave, sea ice concentration dataset was used to create an index classification algorithm that categorized the formation and dissolution of the North Water Polynya from 1979 to 2012. Multiple years were classified as atypical, with the polynya forming earlier, the ice arch not forming at Smith Sound, or the ice arch not forming at all. Secondly, we compare and contrast atmospheric factors that influenced the formation of the ice arch during a typical (2010-2011) and an atypical (2009-2010) formation year. A significant southerly wind event in 2009-2010 could have displaced the ice pack and prevented the consolidation of the ice arch. The importance of the changing ice pack in Nares Strait to the formation of the polynya is also discussed. / May 2016