Contemporary climate change and permafrost thaw are influencing the physical hydrology and water quality of Arctic freshwater systems. In the Western Canadian Arctic, thaw-driven mass wasting has set the context for most water quality studies. Few studies have examined aquatic systems not impacted by physical disturbances to the permafrost. As a result, our understanding of how water quality varies spatially (in response to changes in permafrost thaw and terrain conditions) and temporally (in response to seasonal variability in precipitation, thaw, and flow pathways) is limited.  The purpose of this investigation is to examine the seasonal chemistry of two small Arctic rivers not influenced by physical permafrost disturbances. Rengleng River and Caribou Creek are situated within a region of continuous permafrost. The recent emergence of late-winter discharge at both sites is unique for small rivers in this region and suggests an increase in groundwater flow contributions. In 2021, water samples were collected up to three times monthly from late-winter to late-summer and analyzed for carbon, nitrogen, phosphorus, and mineral ions. To ascertain the source of winter streamflow, water samples were analyzed for 14C Age. Supplementary water quality data is available for 2019 and 2020. Meteorological, flow, active layer extent, and detailed terrain information is also available. We examine how water quality responds to winter discharge, spring snowmelt, and seasonal fluctuations in active layer thickness, as well as the physical characteristics of each watershed.

Primary Presenter: Erika Hille, Queens University (erika.hille@queensu.ca)

Authors:

Melissa Lafreniere, Queens University  (melissa.lafreniere@queensu.ca)

Scott Lamoureux, Queens University  (scott.lamoureux@queenu.ca)

Steve Kokelj, Northwest Territories Geological Survey  (steve_kokelj@gov.nt.ca)