Controls on stream hydrochemistry dynamics in a high Arctic snow-covered watershed
Docherty, Catherine L.;
Milner, Alexander M.;
Christoffersen, Kirsten Seestern;
Christofferson, Kirsten Seestern;
Hannah, David M.
Arctic streams are highly sensitive to climate change due to warmer air temperatureand increased precipitation associated with an encroaching low Arctic climatic zoneinto currently high‐Arctic coastal areas. Increases in nivation processes and perma-frost degradation will lead to potential changes in stream physicochemical habitat,although these impacts are poorly understood. To address this gap, physicochemicalhabitat characteristics in streams around Zackenberg in Northeast Greenland NationalPark were investigated during the summers of 2013 to 2016. Streams with differentsized snowpacks represented both low and high snowfall conditions leading to differ-ent nivation processes. Streams with larger snowpacks displayed lower channel stabil-ity, with higher channel mobility, suspended sediment and solute concentrations.Suspended sediment concentration was identified as a key driver of stream soluteconcentrations, and varying snowpack levels caused high interannual variability in sol-ute concentrations. Winter snowpack size was confirmed to be an important driver ofstream physicochemical habitat in an Arctic region with low glacial cover. We predictclimate change will strongly impact stream hydrochemistry in this region throughincreased nivation processes alongside active layer thickening and solifluction,thereby increasing stream suspended sediment and solute concentrations. These find-ings indicate that hydrochemistry was principally a function of erosion, with variationbeing determined by spatial and temporal patterns in erosional processes, and as such,alternative methods to fingerprint water sources should be considered in this region.