Enhanced response of global wetland methane emissions to the 2015-2016 El Nino-Southern Oscillation event ...

• Main Authors: Zhang, Zhen, Zimmermann, Niklaus E., Calle, Leonardo, Hurtt, George, Chatterjee, Abhishek, Poulter, Benjamin
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2018
• Subjects: DGVM; global methane budget; ENSO; greenhouse gas; permafrost
• Online Access: https://dx.doi.org/10.3929/ethz-b-000275577; http://hdl.handle.net/20.500.11850/275577

Wetlands are thought to be the major contributor to interannual variability in the growth rate of atmospheric methane (CH4) with anomalies driven by the influence of the El Niño-Southern Oscillation (ENSO). Yet it remains unclear whether (i) the increase in total global CH4 emissions during El Niño versus La Niña events is from wetlands and (ii) how large the contribution of wetland CH4 emissions is to the interannual variability of atmospheric CH4. We used a terrestrial ecosystem model that includes permafrost and wetland dynamics to estimate CH4 emissions, forced by three separate meteorological reanalyses and one gridded observational climate dataset, to simulate the spatio-temporal dynamics of wetland CH4 emissions from 1980–2016. The simulations show that while wetland CH4 responds with negative annual anomalies during the El Niño events, the instantaneous growth rate of wetland CH4 emissions exhibits complex phase dynamics. We find that wetland CH4 instantaneous growth rates were declined at the onset ... : Environmental Research Letters, 13 (7) ...