Open AccessRain-fed pulses of methane from East Africa during 2018–2019 contributed to atmospheric growth rate
Author(s) -
Mark F. Lunt,
Paul I. Palmer,
Alba Lorente,
Tobias Borsdorff,
Jochen Landgraf,
Robert J. Parker
Publication year - 2021
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/abd8fa
Subject(s) - environmental science , methane , atmospheric sciences , climatology , atmospheric methane , wetland , greenhouse gas , oceanography , geology , chemistry , ecology , organic chemistry , biology
East Africa is a key location for wetland emissions of methane (CH 4 ), driven by variations in rainfall that are in turn influenced by sea-surface temperature gradients over the Indian Ocean. Using satellite observations of CH 4 and an atmospheric chemistry-transport model, we quantified East African CH 4 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 CH 4 emissions of 6.2 ± 0.3 Tg CH 4 and 8.6 ± 0.3 Tg CH 4 , 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 CH 4 budget.