River Inflow Dominates Methane Emissions in an Arctic Coastal System

UBC Faculty Research and Publications

River Inflow Dominates Methane Emissions in an Arctic Coastal System Manning, Cara C.; Preston, Victoria L.; Jones, Samantha F.; Michel, Anna P. M.; Nicholson, David P.; Duke, Patrick J.; Ahmed, Mohamed M. M.; Manganini, Kevin; Else, Brent G. T.; Tortell, Philippe Daniel, 1972-

Abstract

We present a year‐round time series of dissolved methane (CH₄), along with targeted observations during ice melt of CH₄ and carbon dioxide (CO₂) in a river and estuary adjacent to Cambridge Bay, Nunavut, Canada. During the freshet, CH₄ concentrations in the river and ice‐covered estuary were up to 240,000% saturation and 19,000% saturation, respectively, but quickly dropped by >100‐fold following ice melt. Observations with a robotic kayak revealed that river‐derived CH₄ and CO₂ were transported to the estuary and rapidly ventilated to the atmosphere once ice cover retreated. We estimate that river discharge accounts for >95% of annual CH₄ sea‐to‐air emissions from the estuary. These results demonstrate the importance of resolving seasonal dynamics in order to estimate greenhouse gas emissions from polar systems.

Item Metadata

Title	River Inflow Dominates Methane Emissions in an Arctic Coastal System
Creator	Manning, Cara C.; Preston, Victoria L.; Jones, Samantha F.; Michel, Anna P. M.; Nicholson, David P.; Duke, Patrick J.; Ahmed, Mohamed M. M.; Manganini, Kevin; Else, Brent G. T.; Tortell, Philippe Daniel, 1972-
Publisher	Geophysical Research Letters
Date Issued	2020-04-23
Description	We present a year‐round time series of dissolved methane (CH₄), along with targeted observations during ice melt of CH₄ and carbon dioxide (CO₂) in a river and estuary adjacent to Cambridge Bay, Nunavut, Canada. During the freshet, CH₄ concentrations in the river and ice‐covered estuary were up to 240,000% saturation and 19,000% saturation, respectively, but quickly dropped by >100‐fold following ice melt. Observations with a robotic kayak revealed that river‐derived CH₄ and CO₂ were transported to the estuary and rapidly ventilated to the atmosphere once ice cover retreated. We estimate that river discharge accounts for >95% of annual CH₄ sea‐to‐air emissions from the estuary. These results demonstrate the importance of resolving seasonal dynamics in order to estimate greenhouse gas emissions from polar systems.
Subject	greenhouse gases; biogeochemistry; Arctic coastal waters; biogeochemical sensing; seasonal cycles; methane
Genre	Article; Postprint
Type	Text
Language	eng
Date Available	2020-10-23
Provider	Vancouver : University of British Columbia Library
Rights	Attribution-NoDerivatives 4.0 International
DOI	10.14288/1.0394393
URI	http://hdl.handle.net/2429/76052
Affiliation	Science, Faculty of; Non UBC; Botany, Department of; Earth, Ocean and Atmospheric Sciences, Department of
Citation	Manning, C. C., Preston, V. L., Jones, S. F., Michel, A. P. M., Nicholson, D. P., Duke, P. J., et al. (2020). River inflow dominates methane emissions in an Arctic coastal system. Geophysical Research Letters, 47, e2020GL087669
Publisher DOI	10.1029/2020GL087669
Peer Review Status	Reviewed
Scholarly Level	Faculty; Researcher; Postdoctoral; Graduate
Copyright Holder	American Geophysical Union
Rights URI	http://creativecommons.org/licenses/by-nd/4.0/
Aggregated Source Repository	DSpace

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