The role of microbial dynamics of methanogens and high affinity methanotrophs in current and future net land methane emissions in the Arctic
Abstract
Methane emissions from arctic soils (north of 50 °N) have been extensively studied due to their potential role as a significant methane source when permafrost thaws. However, this methane source might have been overestimated as high affinity methanotrophs (HAM) identified in arctic mineral soils have not been considered. Previous mechanistically-based methane models were typically parameterized using observed methane emission data from organic soils under anaerobic conditions without considering methane consumption in mineral soils. Here we integrated microbial dynamics, i.e., temporal changes in their active biomass abundance, of both methanogens and HAM into a biogeochemistry model that considers the effects of permafrost dynamics to re-assess the net arctic methane emissions. Here we will report the comparison between the new model estimates and the simulations using a previous model that has not considered microbial and permafrost dynamics for the contemporary period (2000-2016). The revised estimates are also evaluated using site-level, regional, and pan-arctic observations. Moreover, we will also report the new model projections of wetland methane emissions for the 21stcentury. Our results highlight the urgent need for including HAM and microbial dynamics in mechanistic methane models to better understand and constrain the current and future methane budget in the Arctic.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.B24B..08Z
- Keywords:
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- 0365 Troposphere: composition and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0490 Trace gases;
- BIOGEOSCIENCES;
- 0497 Wetlands;
- BIOGEOSCIENCES;
- 1615 Biogeochemical cycles;
- processes;
- and modeling;
- GLOBAL CHANGE