Water temperature dynamics in High Arctic river basins
Version of Record online: 28 JUN 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Volume 27, Issue 20, pages 2958–2972, 30 September 2013
How to Cite
Blaen, P. J., Hannah, D. M., Brown, L. E. and Milner, A. M. (2013), Water temperature dynamics in High Arctic river basins. Hydrol. Process., 27: 2958–2972. doi: 10.1002/hyp.9431
- Issue online: 2 SEP 2013
- Version of Record online: 28 JUN 2012
- Accepted manuscript online: 1 JUN 2012 02:14PM EST
- Manuscript Accepted: 29 MAY 2012
- Manuscript Received: 13 OCT 2011
- water temperature;
- thermal regime;
Despite the high sensitivity of polar regions to climate change and the strong influence of temperature upon ecosystem processes, contemporary understanding of water temperature dynamics in Arctic river systems is limited. This research gap was addressed by exploring high-resolution water column thermal regimes for glacier-fed and non-glacial rivers at eight sites across Svalbard during the 2010 melt season. Mean water column temperatures in glacier-fed rivers (0.3–3.2 °C) were lowest and least variable near the glacier terminus but increased downstream (0.7–2.3 °C km–1). Non-glacial rivers, where discharge was sourced primarily from snowmelt runoff, were warmer (mean: 2.9–5.7 °C) and more variable, indicating increased water residence times in shallow alluvial zones and increased potential for atmospheric influence. Mean summer water temperature and the magnitude of daily thermal variation were similar to those of some Alaskan Arctic rivers but low at all sites when compared with alpine glacierized environments at lower latitudes. Thermal regimes were correlated strongly (p < 0.01) with incoming short-wave radiation, air temperature, and river discharge. Principal drivers of thermal variability were inferred to be (i) water source (i.e. glacier melt, snowmelt, groundwater); (ii) exposure time to the atmosphere; (iii) prevailing meteorological conditions; (iv) river discharge; (v) runoff interaction with permafrost and buried ice; and (vi) basin-specific geomorphological features (e.g. channel morphology). These results provide insight into the potential changes in high-latitude river systems in the context of projected warming in polar regions. We hypothesize that warmer and more variable temperature regimes may prevail in the future as the proportion of bulk discharge sourced from glacial meltwater declines and rivers undergo a progressive shift towards snow water and groundwater sources. Importantly, such changes could have implications for aquatic species diversity and abundance and influence rates of ecosystem functioning in high-latitude river systems. Copyright © 2012 John Wiley & Sons, Ltd.