Surface water inundation in the boreal-Artic: potential impacts on regional methane emissions

Authors

J. D. Watts, University of Montana - MissoulaFollow
John S. Kimball, University of Montana - MissoulaFollow
Annett Bartsch, University of Salzburg
Kyle C. McDonald, City College of New York

Document Type

Article

Publication Title

Environmental Research Letters

Publisher

IOP Publishing

Publication Date

6-30-2014

Volume

9

Disciplines

Biology | Life Sciences

Abstract

Northern wetlands may be vulnerable to increased carbon losses from methane (CH₄), a potent greenhouse gas, under current warming trends. However, the dynamic nature of open water inundation and wetting/drying patterns may constrain regional emissions, offsetting the potential magnitude of methane release. Here we conduct a satellite data driven model investigation of the combined effects of surface warming and moisture variability on high northern latitude (45° N) wetland CH₄ emissions, by considering (1) sub-grid scale changes in fractional water inundation (Fw) at 15 day, monthly and annual intervals using 25 km resolution satellite microwave retrievals, and (2) the impact of recent (2003-11) wetting/drying on northern CH₄ emissions. The model simulations indicate mean summer contributions of 53 Tg CH₄ yr^-1 from boreal-Arctic wetlands. Approximately 10% and 16% of the emissions originate from open water and landscapes with emergent vegetation, as determined from respective 15 day Fw means or maximums, and significant increases in regional CH₄ efflux were observed when incorporating satellite observed inundated land fractions into the model simulations at monthly or annual time scales. The satellite Fw record reveals widespread wetting across the Arctic continuous permafrost zone, contrasting with surface drying in boreal Canada, Alaska and western Eurasia. Arctic wetting and summer warming increased wetland emissions by 0.56 Tg CH₄ y^r-1 compared to the 2003-1 mean, but this was mainly offset by decreasing emissions (-0.38 Tg CH₄ yr^-1) in sub-Arctic areas experiencing surface drying or cooling. These findings underscore the importance of monitoring changes in surface moisture and temperature when assessing the vulnerability of boreal-Arctic wetlands to enhanced greenhouse gas emissions under a shifting climate.

Keywords

Arctic, wetlands, permafrost, inundation, methane, microwave remote sensing, carbon

DOI

10.1088/1748-9326/9/7/075001

Rights

© 2014 IOP Publishing Ltd

Creative Commons License

This work is licensed under a Creative Commons Attribution 3.0 License.

Recommended Citation

Watts, J. D.; Kimball, John S.; Bartsch, Annett; and McDonald, Kyle C., "Surface water inundation in the boreal-Artic: potential impacts on regional methane emissions" (2014). Biological Sciences Faculty Publications. 406.
https://scholarworks.umt.edu/biosci_pubs/406