Summer hydroclimatology of an extensive low-gradient wetland: Polar Bear Pass, Bathurst Island, Nunavut, Canada

Polar Bear Pass (PBP) (75°40′N, 98°30′W) is considered a critical wetland area for migratory birds, caribou and muskox. Little is known of its climatology and hydrology. Here we evaluate both the short-term and long-term summer climatic record for this wetland. A 10 m high automatic weather station (AWS) was established here 27 years ago, and in 2007 this centrally located AWS was supplemented by three more weather stations placed across the wetland pass. The long-term climate record here indicates little significant departure when compared to the long-term climate means (1971–2005) at Resolute Bay, a government weather station lying 90 km to the southwest (74°43′N, 94°59′W). Exceptions exist for July minimum air temperature (PBP > Resolute) and number of days in June, July and August < 0°C (PBP < Resolute). Climate variability from year to year remains the norm. Radiation receipt, air temperature, humidity and wind speed vary little across the wetland pass, while terrain-modified fluxes do. The precipitation regime is similar to Resolute Bay but local site conditions modify the amounts. In 2007, July evaporation levels were twice as high as that of 2008; more akin to Low Arctic sites. As yet, no clear trend in long-term climatic signals can be established.