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Rain-fed pulses of methane from East Africa during 2018-2019 contributed to atmospheric growth rate

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journal contribution
posted on 09.09.2021, 10:15 by Mark F Lunt, Paul Palmer, Alba Lorente, Tobias Borsdorff, Jochen Landgraf, Robert J Parker, Hartmut Boesch
East Africa is a key location for wetland emissions of methane (CH4), driven by variations in rainfall that are in turn influenced by sea-surface temperature gradients over the Indian Ocean. Using satellite observations of CH4 and an atmospheric chemistry-transport model, we quantified East African CH4 emissions during 2018 and 2019 when there was 3-σ anomalous rainfall during the long rains (March-May) in 2018 and the short rains (October-December) in 2019. These rainfall anomalies resulted in CH4 emissions of 6.2 ± 0.3 Tg CH4 and 8.6 ± 0.3 Tg CH4, in each three month period, respectively, and represent a 10% and 37% increase compared to the equivalent season in the opposite year, when rainfall was close to the long-term seasonal mean. We find the additional short rains emissions were equivalent to over a quarter of the growth in global emissions in 2019, highlighting the disproportionate role of East Africa in the global CH4 budget.

Funding

Methane Observations and Yearly Assessments (MOYA) project (NE/N015916/1)

National Centre for Earth Observation funded by the National Environment Research Council (NE/R016518/1)

UK National Centre for Earth Observation (NE/R016518/1 and NE/N018079/1)

ESA GHG-CCI and Copernicus C3S projects

History

Citation

Environ. Res. Lett. 16 024021

Author affiliation

National Centre for Earth Observation, University of Leicester

Version

VoR (Version of Record)

Published in

Environmental Research Letters

Volume

16

Issue

2

Publisher

Institute of Physics (IoP)

issn

1748-9326

eissn

1748-9326

Acceptance date

06/01/2021

Copyright date

2021

Available date

09/09/2021

Language

English