Review status: this preprint is currently under review for the journal ACP.
Large and increasing methane emissions from Eastern Amazonia
derived from satellite data, 2010–2018
Chris Wilson1,2,Martyn P. Chipperfield1,2,Manuel Gloor3,Robert J. Parker4,5,Hartmut Boesch4,5,Joey McNorton6,Luciana V. Gatti7,John B. Miller8,Luana S. Basso7,and Sarah A. Monksa,bChris Wilson et al.Chris Wilson1,2,Martyn P. Chipperfield1,2,Manuel Gloor3,Robert J. Parker4,5,Hartmut Boesch4,5,Joey McNorton6,Luciana V. Gatti7,John B. Miller8,Luana S. Basso7,and Sarah A. Monksa,b
1National Centre for Earth Observation, University of Leeds, Leeds, UK
2School of Earth and Environment, University of Leeds, UK
3School of Geography, University of Leeds, Leeds, UK
4Earth Observation Science, School of Physics and Astronomy, University of Leicester, Leicester, UK
5National Centre for Earth Observation, University of Leicester, Leicester, UK
6European Centre for Medium-Range Weather Forecasts, Reading, UK
7Earth System Science Center (CCST), National Institute for Space Research (INPE), Av. Dos Astronautas, 1758, 12.227-010, São José dos Campos, SP, Brazil
8Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA
aformerly at: CIRES, University of Colorado Boulder, Boulder, CO, USA
bformerly at: Chemical Sciences Division, NOAA, Earth System Research Laboratory, Boulder, CO, USA
1National Centre for Earth Observation, University of Leeds, Leeds, UK
2School of Earth and Environment, University of Leeds, UK
3School of Geography, University of Leeds, Leeds, UK
4Earth Observation Science, School of Physics and Astronomy, University of Leicester, Leicester, UK
5National Centre for Earth Observation, University of Leicester, Leicester, UK
6European Centre for Medium-Range Weather Forecasts, Reading, UK
7Earth System Science Center (CCST), National Institute for Space Research (INPE), Av. Dos Astronautas, 1758, 12.227-010, São José dos Campos, SP, Brazil
8Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA
aformerly at: CIRES, University of Colorado Boulder, Boulder, CO, USA
bformerly at: Chemical Sciences Division, NOAA, Earth System Research Laboratory, Boulder, CO, USA
Received: 30 Oct 2020 – Accepted for review: 06 Nov 2020 – Discussion started: 10 Nov 2020
Abstract. We use a global inverse model, satellite data and flask measurements to estimate methane (CH4) emissions from South America, Brazil and the basin of the Amazon River for the period 2010–2018. We find that emissions from Brazil have risen during this period, most quickly in the Eastern Amazon Basin, and that this concurrent with increasing surface temperatures in this region. Brazilian CH4 emissions rose from 49.8 ± 5.4 Tg(CH4)/yr in 2010–2013 to 55.6 ± 5.2 Tg(CH4)/yr in 2014–2017, with the wet season of December–March having the largest positive trend in emissions. We derive no significant trend in regional emissions from fossil fuels during this period. We find that our posterior distribution of emissions within South America is significantly and consistently changed from our prior estimates, with the strongest emission sources being in the far north of the continent and to the south and south-east of the Amazon Basin, near the mouth of the Amazon and in other wetland regions. We derive particularly large emissions during the wet season of 2013/14, when flooding was prevalent over larger regions than normal within the Amazon Basin. We compare our posterior CH4 mole fractions, derived from posterior fluxes, to independent observations of CH4 mole fraction taken at five lower to mid tropospheric vertical profiling sites over the Amazon and find that our posterior fluxes outperform prior fluxes at all locations. In particular the large emissions from the eastern Basin are shown to be in good agreement with independent observations made at Santarém, a location which has long displayed higher mole fractions of atmospheric CH4 in contrast with other Basin locations. We show that a bottom-up flux model cannot match the variation in annual fluxes, nor the positive trend in emissions, produced by the inversion. Our results show that the Amazon alone was responsible for 24 ± 18 % of the total global increase in CH4 flux during the study period, and it may contribute further in future due to its sensitivity to temperature changes.
Methane (CH4) is an important greenhouse gas emitted from wetlands like those found in the basin of the Amazon River. Using an atmospheric model and observations from the GOSAT satellite, we quantified CH4 emissions from Amazonia during the previous decade. We found that the largest emissions came from a region in the eastern Basin, and that emissions there were rising faster than in other areas of South America. This finding was supported by CH4 observations made on aircraft within the Basin.
Methane (CH4) is an important greenhouse gas emitted from wetlands like those found in the basin...