Warming effects of spring rainfall increase methane emissions from thawing permafrost

Geophysical Research Letters
By: , and 

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Abstract

Methane emissions regulate the near‐term global warming potential of permafrost thaw, particularly where loss of ice‐rich permafrost converts forest and tundra into wetlands. Northern latitudes are expected to get warmer and wetter, and while there is consensus that warming will increase thaw and methane emissions, effects of increased precipitation are uncertain. At a thawing wetland complex in Interior Alaska, we found that interactions between rain and deep soil temperatures controlled methane emissions. In rainy years, recharge from the watershed rapidly altered wetland soil temperatures, warming the top ~80 cm of soil in spring and summer and cooling it in autumn. When soils were warmed by spring rainfall, methane emissions increased by ~30%. The warm, deep soils early in the growing season likely supported both microbial and plant processes that enhanced emissions. Our study identifies an important and unconsidered role of rain in governing the radiative forcing of thawing permafrost landscapes.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Warming effects of spring rainfall increase methane emissions from thawing permafrost
Series title Geophysical Research Letters
DOI 10.1029/2018GL081274
Volume 46
Issue 3
Year Published 2019
Language English
Publisher American Geophysical Union
Contributing office(s) Volcano Science Center, Volcano Hazards Program, Geology, Minerals, Energy, and Geophysics Science Center
Description 9 p.
First page 1393
Last page 1401
Country United States
State Alaska