Topographic shading influences cryoconite morphodynamics and carbon exchange.

• Published in: Arctic, Antarctic, and Alpine Research
• Main Authors: Cook, J. M., Sweet, Michael J., Cavalli, Ottavia, Taggart, Angus, Edwards, Arwyn
• Other Authors: University of Derby, Aberystwyth University, University of Sheffield
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor and Francis 2018
• Subjects: Biogeochemistry; Carbon cycling; Biocryomorphology; Cellular biophysics; Arctic; Croft; Watkins; Antarctic and Alpine Research; Ice Sheet
• Online Access: http://hdl.handle.net/10545/622353; https://doi.org/10.1080/15230430.2017.1414463

Cryoconite holes are the most active and diverse microbial habitats on glacier and ice-sheet surfaces. In this article the authors demonstrate that the shape of cryoconite holes varies depending on ice-surface topography and that this has implications for the carbon cycling regime within. Net ecosystem production is shown to be controlled primarily by sediment thickness within holes. The authors show that irregular hole shapes are indicative of hole migration away from topographic shade, which promotes carbon fixation at the mesoscale on ice surfaces. A cellular automaton is used in conjunction with sediment-delivery experiments to show that migration is the result of simple sediment transfer processes, implying a relationship between ice-surface evolution and cryoconite biogeochemistry that has not previously been examined. The authors gratefully acknowledge funding from the British Society for Geomorphology, Mount Everest Foundation, Gino Watkins Memorial Fund, Andrew Croft Memorial Fund, Scottish Arctic Club, Gilchrist Educational Fund, and Rolex Awards for Enterprise and Gradconsult. JC also acknowledges UK-funded Natural Environment Research Council Consortium Grant “Black and Bloom” (NE/ M021025/1).