Multi-year variations in High Arctic river temperatures in response to climate variability

Water temperature measurements (2004-2016) from two small rivers in the High Arctic were analyzed in order to determine the effects of climate variability on thermal regime and the sensitivity to climate change. The East and West rivers (unofficial names) drain similar watersheds (11.6 and 8.0 km2, respectively) and are located at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Canada (74째55' N, 109째35' W). Differences in seasonal timing of river temperatures were evident when comparing the coldest and warmest years of the study period, and across different discharge conditions. Snow melt runoff is characterized by uniformly cold water (~0-1째C) over a wide range of discharge conditions, followed by warming water temperatures during flow recession. The rivers showed varying sensitivity to mid-summer air temperature conditions in a given year, with warmer years indicating high correlation (r2= 0.794-0.929), while colder years showed reduced correlation (r2= 0.368-0.778). River temperatures reached levels which are reported to negatively affect fish and other cold-water aquatic species (>18 째C) with greater frequency and duration during the warmest years. These results provide a basis to further enhance prediction of river thermal conditions to assess ecosystem health in a river system and to refine insights into the effects of climate change on High Arctic aquatic ecosystems.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author