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Effects of Chemical Feedbacks on Decadal Methane Emissions Estimates

Nguyen, Newton H. and Turner, Alexander J. and Yin, Yi and Prather, Michael J. and Frankenberg, Christian (2020) Effects of Chemical Feedbacks on Decadal Methane Emissions Estimates. Geophysical Research Letters, 47 (3). Art. No. e2019GL085706. ISSN 0094-8276. https://resolver.caltech.edu/CaltechAUTHORS:20200122-145933294

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Abstract

The coupled chemistry of methane, carbon monoxide (CO), and hydroxyl radical (OH) can modulate methane's 9‐year lifetime. This is often ignored in methane flux inversions, and the impacts of neglecting interactive chemistry have not been quantified. Using a coupled‐chemistry box model, we show that neglecting the effect of methane source perturbation on [OH] can lead to a 25% bias in estimating abrupt changes in methane sources after only 10 years. Further, large CO emissions, such as from biomass burning, can increase methane concentrations by extending the methane lifetime through impacts on [OH]. Finally, we quantify the biases of including (or excluding) coupled chemistry in the context of recent methane and CO trends. Decreasing CO concentrations, beginning in the 2000's, have notable impacts on methane flux inversions. Given these nonnegligible errors, decadal methane emissions inversions should incorporate chemical feedbacks for more robust methane trend analyses and source attributions.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1029/2019gl085706DOIArticle
https://github.com/Newton-Climate/Methane_OH_boxRelated ItemCode
ORCID:
AuthorORCID
Nguyen, Newton H.0000-0002-9118-8672
Turner, Alexander J.0000-0003-1406-7372
Yin, Yi0000-0003-4750-4997
Prather, Michael J.0000-0002-9442-8109
Frankenberg, Christian0000-0002-0546-5857
Additional Information:© 2020 American Geophysical Union. Received 7 OCT 2019; Accepted 15 JAN 2020; Accepted article online 16 JAN 2020. This work was supported by a NSF Graduate Research Fellowship (to N. H. Nguyen) and a grant from the Grantham Foundation (to Y. Yin and N. H. Nguyen). A. J. Turner is supported as a Miller Fellow with the Miller Institute for Basic Research in Science at UC Berkeley. The authors declare no conflict of interest. The two‐hemisphere box model can be accessed via Github https://github.com/Newton-Climate/Methane_OH_box; surface observations were accessed from the following sources: CH urn:x-wiley:grl:media:grl60131:grl60131-math-0128 NOAA (ftp://aftp.cmdl.noaa.gov/data/trace_gases/ch4/flask/); MCF NOAA (ftp://aftp.cmdl.noaa.gov/data/hats/solvents/CH3CCl3/); MCF GAGE/AGAGE (http://agage.mit.edu/); and CO NOAA (ftp://aftp.cmdl.noaa.gov/data/trace_gases/co/flask/surface/).
Funders:
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
Grantham FoundationUNSPECIFIED
Miller Institute for Basic Research in ScienceUNSPECIFIED
Issue or Number:3
Record Number:CaltechAUTHORS:20200122-145933294
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20200122-145933294
Official Citation:Nguyen, N. H., Turner, A. J., Yin, Y., Prather, M. J., & Frankenberg, C. (2020). Effects of chemical feedbacks on decadal methane emissions estimates. Geophysical Research Letters, 47, e2019GL085706. https://doi.org/10.1029/2019GL085706
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100855
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:22 Jan 2020 23:09
Last Modified:11 Feb 2020 23:15

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