Ice wedge degradation and CO2 and CH4 emissions in the Tuktoyaktuk Coastlands, NT

• Main Authors: Martin, Abra F., Lantz, Trevor C., Humphreys, Elyn R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2017
• Subjects: Canada; Tuktoyaktuk; Ice; permafrost; wedge*
• Online Access: http://hdl.handle.net/1807/87283; http://www.nrcresearchpress.com/doi/abs/10.1139/AS-2016-0011

Increases in ground temperature make soil organic carbon in permafrost environments highly vulnerable to release to the atmosphere. High-centred polygonal terrain is a form of patterned ground that may include areas that act as large sources of carbon to the atmosphere because thawing ice-wedges can result in increased ground temperatures, soil moisture and thaw depth. To evaluate the effect of ice wedge degradation on carbon flux, carbon emissions were characterized at two polygonal peatlands in the Tuktoyaktuk Coastlands in northern Canada. Opaque chambers were used to measure CO2 and CH4 emissions from nine non-degraded polygon centres and nine moderately-degraded troughs four times during the growing season. To measure emissions from 10 ponds resulting from severe ice wedge degradation, wind diffusion models were used to characterize fluxes using CO2 and CH4 measurements made in each pond. Our field data show that degraded troughs had increased ground temperature, deeper active layers, and increased CO2 and CH4 emissions. Our study shows that rates of CO2 and CH4 emissions from high-centered polygonal terrain are likely to increase with more widespread melt pond formation in this terrain type. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.