Early spring rain boosts methane from thawing permafrost by 30 percent
http://www.washington.edu/news/2019/02/04/early-rainfall-increases-methane-from-thaw-bog/February 4, 2019
Early spring rain boosts methane from thawing permafrost by 30 percent
Sarah McQuate
UW News
Arctic permafrost is thawing as the Earth warms due to climate change. In some cases, scientists predict that this thawing soil
will release increasing amounts of methane, a potent greenhouse gas, that is known to trap more heat in our planets atmosphere.
Now a University of Washington-led team has found a new reason behind increased methane emissions from a thawing permafrost bog in Alaska: Early spring rainfall warms up the bog and promotes the growth of plants and methane-producing microbes. The team showed that early precipitation in 2016 warmed the bog about three weeks earlier than usual, and increased the bogs methane emissions by 30 percent compared to previous years.
These results were recently published in Geophysical Research Letters.
In general, the chance of generating methane goes up with increased rainfall because soils get waterlogged. But what we see here is different, said corresponding author
Rebecca Neumann, an associate professor in the UW Department of Civil & Environmental Engineering. Early rainfall sent a slog of warm water moving into our bog. We believe microbes in the bog got excited because they were warmed up, so they released nutrients from the soil that allowed more plant growth. Methane production and emission are tightly linked with soil temperature and plant growth.
Our results emphasize that these permafrost regions are sensitive to the thermal effects of rain, and because were anticipating that these environments are going to get wetter in the future, we could be seeing increases in methane emissions that we werent expecting.
http://dx.doi.org/10.1029/2018GL081274