Polar Bear Pass (PBP), Bathurst Island, Nunavut (75^o40’N, 98^o30’W) can be described as an extensive low-gradient wetland (100 km²). It has been designated a wildlife sanctuary, so is considered a critical wetland area for migratory birds, caribou and muskox. Polar bears frequently traverse the wetland. The biology of this area is well known but less is known of its hydrology and local climate. Wetlands are considered source and sinks of atmospheric gases and the climate signal influences the wetland’s hydrology by determining the timing and rate of snowmelt, ground thaw, freeze-back and evaporative demand. Future changes in climate may modify water flow pattern and storage in this wetland, eventually disrupting vegetation and grazing patterns.

A 10 metre high automatic weather station (AWS) was established about 27 years ago at PBP. The station is centrally located in the pass, located on a polar desert ridge about 60 m above the pass. Hourly climate data (e.g. radiation, temperature, wind) is collected year round, though the site has not been visited on a regular basis. In 2007 & 2008, as part of the IPY funded project Polar Terrestrial Freshwater: State and Flow to the Ocean, this main weather station was supplemented with a series of roving weather stations placed across the pass. These stations were equipped with similar equipment as the main AWS, and recording raingauges were added. Our aim is to evaluate this wetland’s present hydrologic regime and future sustainability.

In this report we examine both the long and short-term climatic record for PBP for the months June, July & August, since this is the most hydrologically dynamic period. Daily climate data, since 1982 is also related to the nearest government weather station, Resolute Bay, about 100 km away. Finally, we examine a range of years (cool, average, warm) and consider climate variability across the pass.