Lessons learned from monitoring the stable water isotopic variability in precipitation and streamflow across a snow-dominated subarctic catchment

Abstract

Lessons learned from monitoring the stable water isotopic variability in precipitation and streamflow across a snow-dominated subarctic catchment Arctic, Antarctic and Alpine research, 50(1): e1454778 https://doi.org/10. 1080/15230430.2018.1454778 Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. This empirical study explores shifts in stable water isotopic composition for a subarctic catchment located in northern Sweden as it transitions from spring freshet to summer low flows. Relative changes in the isotopic composition of streamflow across the main catchment and fifteen nested subcatchments are characterized in relation to the isotopic composition of precipitation. With our sampling campaign, we explore the variability in stream-water isotopic composition that originates from precipitation as the input shifts from snow to rain and as landscape flow pathways change across scales. The isotopic similarity of high-elevation snowpack water and early season rainfall water seen through our sampling scheme made it difficult to truly isolate the impact of seasonal precipitation phase change on stream-water isotopic response. This highlights the need to explicitly consider the complexity of arctic and alpine landscapes when designing sampling strategies to characterize hydrological variability via stable water isotopes. Results show a potential influence of evaporation and source water mixing both spatially (variations with elevation) and temporally (variations from post-freshet to summer flows) on the composition of stream water across Miellajokka. As such, the data collected in this empirical study allow for initial conceptualization of the relative importance of, for example, hydrological connectivity within this mountainous, subarctic landscape. ARTICLE HISTORY

How catchment characteristics influence hydrological pathways and travel times in a boreal landscape

“…The distributions were analysed using four statistical measurement tools, the arithmetic mean, the geometric mean, the median, and the standard deviation (SD). The arithmetic mean, the geometric mean, and the median are common choices to describe the central tendency of a distribution (Destouni et al, 2001;Kaandorp et al, 2018;Massoudieh et al, 2012Massoudieh et al, , 2017Unlu et al, 2001), which all have their strengths and weaknesses. If the distribution is not significantly skewed, the SD is smaller than half of the average (Taagepera, 2008).…”

Nutrients influence seasonal metabolic patterns and total productivity of Arctic streams

“…The hydrological patterns in this catchment are described by Lyon et al (2018) and are shaped by a clear mountain-to-valley transition (e.g., Covino and McGlynn 2007). In short, above the tree line, the Miellajokka catchment is steeper and represents a water collection zone where the streams are dominated by precipitation inputs.…”

Stream metabolism controls diel patterns and evasion of CO2 in Arctic streams

“…Climate in the Miellajokka catchment is characterized by long winters with precipitation as snow from October to May and a short terrestrial growing season from June to September (Christensen et al, 2012). Hydrologic patterns reflect the seasonal climate regime, with a spring flood in May or June during snow melt (discharge at the outlet of 20-25 m 3 /s), and base flow of about 0.05-0.1 m 3 /s during the autumn and winter (Lyon et al, 2018). Dissolved organic carbon (DOC) in Miellajokka can reach 8-10 mg C/L during spring flood and decrease to about 2 mg C/L during summer base flow (Giesler et al, 2014).…”