River Inflow Dominates Methane Emissions in an Arctic Coastal System
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 23, 2020
- Source ID
- 10.1029/2020gl087669
Entities
People
- Anna P. M. Michel
- Brent Else
- Cara C. Manning
- David Nicholson
- Kevin Manganini
- Mohamed Ahmed
- Patrick J. Duke
- Philippe D Tortell
- Samantha F. Jones
- Victoria Preston
Organizations
- Marine Environmental Observation Prediction and Response Network
- Massachusetts Institute of Technology
- Natural Sciences and Engineering Research Council
- United States Department of Defense
- University of British Columbia
- University of Calgary
- University of Victoria
- Woods Hole Oceanographic Institution