Large methane emissions from Amazonian floodplain trees

Blog Author: Emanuel Gloor, University of Leeds

A recent study led by Sunitha Pangala presented the discovery and showed the importance of a previously unknown conduit of methane from floodplains to the atmosphere in the Amazon. The conduit are trees. To demonstrate the importance of this conduit two approaches have been pursued. On the one hand methane flux from tree stems has been measured in floodplain trees of many river stems of the Amazon and for a large number of trees. This data was up-scaled using area estimates of seasonally flooded floodplains.

Sampling set-up for methane from tree stems. Photo Credit: Sunitha Panagala

Setting up of methane tree sampling equipment. Photo credit: Sunitha Pangala

Aircraft were used to regularly (bi-weekly) take vertical profile samples of the lower troposphere methane concentration field. These data together with a back-trajectory based atmospheric inverse transport model were used to estimate the total Amazon basin methane balance. This tropospheric methane sampling program is being led by Luciana Gatti at INPE in Sao Jose dos Campos, Brazil.

While there is disagreement between upscaling of previously known methane flux processes and the aircraft based methane balance, inclusion of the discovered additional flux path leads to good agreement between the two approaches. The discovery of the tree conduit is important because the Amazon contributes a substantial fraction of methane emissions from wetlands globally. This contribution is approximately 8-10% of all contemporary methane emissions to the atmosphere.

Besides Sunitha Pangala and Luciana Gatti, scientists from several other institutions were involved in the study including from the Open University, NOAA, ESRL and University of Leeds.

The full article is available here:

Large emissions from floodplain trees close the Amazon methane budget, Sunitha R. Pangala, Alex Enrich-Prast, Luana S. Basso, Roberta Bittencourt Peixoto, David Bastviken, Edward Hornibrook, Luciana V. Gatti, Humberto Marotta Ribeiro, Wanderley Rodrigues Bastos, Olaf Malm, Emanuel Gloor, John Miller, Vincent Gauci (2017) Nature, 552, 230–234, doi:10.

Moorland fires – BBC film of MOYA flight

This July we had an exciting unplanned measurement flight.
MOYA flight hours were used for James Lee, University of York, and Grant Allen, Manchester University, and their teams to sample over the moorland fires burning in northern England.

Moorland fires over Northern England. Photo Credit: North Yorkshire Fire Services

The air samples are going to give a useful comparison with the Senegal fires the MOYA flights studied last year, and the measurements from next year’s Ugandan campaign.

Sampling over a forest fire in Senegal from the FAAM aircraft, March 2017. Photo Credit: Axel Wellpott

 

Find the full BBC video here. 
BBC report:
“Scientists are flying a lab-on-an-aeroplane through the smoke of wildfires in the north of England, testing the air as they go.Fires like the one on Saddleworth Moor are predicted to be more common than usual across the UK and Europe this summer, raising concerns about pollution.BBC Science Correspondent Victoria Gill joined researchers on a converted passenger plane run by the Natural Environment Research Council.”

Methane session Open for Abstracts – AGU Washington

The MOYA projects PI Euan Nisbet will be convening a session on methane in the AGU Fall Meeting. This years AGU will be held in Washington, D.C. from  the 10th-14th of December. Abstract submission closes on the 1st of August 2018 so get writing!

Sampling methane emissions from cows in Zimbabwe

The global burden of atmospheric methane has exhibited periods of both rapid growth and stagnation over the past two decades, with unexplained rapid growth since 2014. This growth has been accompanied by a negative isotopic shift (δ13CCH4), reversing the trend of the past two centuries. Methane does not have a single dominant source, but rather a wide spectrum of anthropogenic and natural sources. This diversity of uncertain sources has led to a number of recent explanations for recent growth including: tropical wetlands, livestock, fossil fuels (coupled with declining biomass burning), and changes in the methane sink (via reaction with OH). The warming impact of methane’s unexpected growth is now the largest deviation from the Paris Agreement. This session invites work that investigates processes controlling the methane budget using in situ measurements, satellite observations, and modeling, as well as the ways in which emissions can be reduced.