Description and Evaluation of an Emission‐Driven and Fully Coupled Me.pdf (3.66 MB)
Description and Evaluation of an Emission-Driven and Fully Coupled Methane Cycle in UKESM1
journal contributionposted on 2023-02-17, 12:20 authored by GA Folberth, Z Staniaszek, AT Archibald, N Gedney, PT Griffiths, CD Jones, FM O'Connor, RJ Parker, AA Sellar, A Wiltshire
Methane (CH4) is one of the most important trace gases in the atmosphere owing to its role as an exceedingly effective greenhouse gas and atmospheric pollutant. Better understanding of the global methane cycle and its interactions with the Earth system is therefore necessary for robust future projections of anthropogenic climate change and assessments of multi-gas mitigation strategies. Here we present a newly developed methane emission-driven Earth system model to simulate the global methane cycle fully interactively. We provide an evaluation of methane sources and sinks and a full-cycle methane budget and its change over the historic period. We further evaluate the methane atmospheric abundance and lifetime against available observations. The new methane emission-driven model simulates all the components of the methane cycle within observational uncertainty. We calculate a total present-day (2000–2009 decadal average) methane source of 591 Tg(CH4) yr−1 with 197 Tg(CH4) yr−1 coming from wetlands. These sources are nearly balanced by the global methane sinks amounting to 580 Tg (CH4) yr−1; reaction of methane with the hydroxyl radical in the troposphere alone removes 525 Tg(CH4) yr−1. The imbalance between sources and sinks of 11 Tg(CH4) yr−1 represents the atmospheric methane growth rate and is in fairly good agreement with current best estimates of 5.8 Tg(CH4) yr−1 with a range of 4.9–6.6 Tg(CH4) yr−1. At present-day the model shows a maximum systematic negative-bias of approximately 200 ppb in the methane surface mole fraction.
This work was supported by the Joint UK BEIS/Defra Met Office Hadley Centre Climate Programme (GA01101) and the European Union projects CRESCENDO (under grant agreement No 641816) and ESM2025 (under grant agreement No 101003536). ZS was funded by the NERC C-CLEAR DTP (NE/S007164/1). ATA, PTG were funded through NCAS and acknowledge the NERC ACSIS LTSM for support. UKCA is supported by the Met Office and NCAS through the JWCRP who we thank for support. RJP is funded via the UK National Centre for Earth Observation (NE/N018079/1).
CitationFolberth, G. A., Staniaszek, Z., Archibald, A. T., Gedney, N., Griffiths, P. T., Jones, C. D., et al. (2022). Description and evaluation of an emission-driven and fully coupled methane cycle in UKESM1. Journal of Advances in Modeling Earth Systems, 14, e2021MS002982. https://doi.org/10.1029/2021MS002982
Author affiliationNational Centre for Earth Observation, Space Park Leicester
- VoR (Version of Record)
Published inJOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
PublisherAMER GEOPHYSICAL UNION
AIR-QUALITYATMOSPHERIC COMPOSITIONBIOMASS BURNING EMISSIONSCARBON-CYCLECHEMISTRYCLIMATE PROJECTIONSEarth system modelemission-driven simulationENVIRONMENT SIMULATOR JULESfully coupled methane cycleMeteorology & Atmospheric Sciencesmethane earth system feedbacksMODEL DESCRIPTIONPART 2Physical SciencesREACTIVE GASESScience & Technologywetland emissions