A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1

Simple item page
dc.contributor.authorNicely, Julie M.
dc.contributor.authorDuncan, Bryan N.
dc.contributor.authorHanisco, Thomas F.
dc.contributor.authorWolfe, Glenn M.
dc.contributor.authorSalawitch, Ross J.
dc.contributor.authorDeushi, Makoto
dc.contributor.authorHaslerud, Amund S.
dc.contributor.authorJöckel, Patrick
dc.contributor.authorJosse, Béatrice
dc.contributor.authorKinnison, Douglas E.
dc.contributor.authorKlekociuk, Andrew
dc.contributor.authorManyin, Michael E.
dc.contributor.authorMarécal, Virginie
dc.contributor.authorMorgenstern, Olaf
dc.contributor.authorMurray, Lee T.
dc.contributor.authorMyhre, Gunnar
dc.contributor.authorOman, Luke D.
dc.contributor.authorPitari, Giovanni
dc.contributor.authorPozzer, Andrea
dc.contributor.authorQuaglia, Ilaria
dc.contributor.authorRevell, Laura E.
dc.contributor.authorRozanov, Eugene
dc.contributor.authorStenke, Andrea
dc.contributor.authorStone, Kane
dc.contributor.authorStrahan, Susan
dc.contributor.authorTilmes, Simone
dc.contributor.authorTost, Holger
dc.contributor.authorWestervelt, Daniel M.
dc.contributor.authorZeng, Guang
dc.date.accessioned2020-03-24T16:57:37Z
dc.date.available2020-03-24T16:57:37Z
dc.date.issued2020-02-05
dc.description.abstractThe hydroxyl radical (OH) plays critical roles within the troposphere, such as determining the lifetime of methane (CH₄), yet is challenging to model due to its fast cycling and dependence on a multitude of sources and sinks. As a result, the reasons for variations in OH and the resulting methane lifetime (τCH₄), both between models and in time, are difficult to diagnose. We apply a neural network (NN) approach to address this issue within a group of models that participated in the Chemistry-Climate Model Initiative (CCMI). Analysis of the historical specified dynamics simulations performed for CCMI indicates that the primary drivers of τCH₄ differences among 10 models are the flux of UV light to the troposphere (indicated by the photolysis frequency JO¹D), the mixing ratio of tropospheric ozone (O₃), the abundance of nitrogen oxides (NOₓ≡NO+NO₂), and details of the various chemical mechanisms that drive OH. Water vapour, carbon monoxide (CO), the ratio of NO:NOₓ, and formaldehyde (HCHO) explain moderate differences in τCH₄, while isoprene, methane, the photolysis frequency of NO₂ by visible light (JNO₂), overhead ozone column, and temperature account for little to no model variation in τCH₄. We also apply the NNs to analysis of temporal trends in OH from 1980 to 2015. All models that participated in the specified dynamics historical simulation for CCMI demonstrate a decline in τCH₄ during the analysed timeframe. The significant contributors to this trend, in order of importance, are tropospheric O₃, JO¹D, NOₓ, and H₂O, with CO also causing substantial interannual variability in OH burden. Finally, the identified trends in τCH₄ are compared to calculated trends in the tropospheric mean OH concentration from previous work, based on analysis of observations. The comparison reveals a robust result for the effect of rising water vapour on OH and τCH₄, imparting an increasing and decreasing trend of about 0.5 % decade⁻¹, respectively. The responses due to NOₓ, ozone column, and temperature are also in reasonably good agreement between the two studies.en_US
dc.description.sponsorshipThis research has been supported by an appointment to the NASA Postdoctoral Program at the NASA Goddard Space Flight Center, administered by the Universities Space Research Association under contract with NASA; the JSPS KAKENHI (grant no. JP19K12312); China Southern; the Bundesministerium für Bildung und Forschung (BMBF); and the New Zealand Government’s Strategic Science Investment Fund (SSIF).en_US
dc.description.urihttps://www.atmos-chem-phys.net/20/1341/2020/en_US
dc.format.extent21 pagesen_US
dc.genrejournal articlesen_US
dc.identifierdoi:10.13016/m2wadd-nx3p
dc.identifier.citationNicely, Julie M.; Duncan, Bryan N.; Hanisco, Thomas F.; Wolfe, Glenn M.; Salawitch, Ross J.; Deushi, Makoto; Haslerud, Amund S.; Jöckel, Patrick; Josse, Béatrice; Kinnison, Douglas E.; Klekociuk, Andrew; Manyin, Michael E.; Marécal, Virginie; Morgenstern, Olaf; Murray, Lee T.; Myhre, Gunnar; Oman, Luke D.; Pitari, Giovanni; Pozzer, Andrea; Quaglia, Ilaria; Revell, Laura E.; Rozanov, Eugene; Stenke, Andrea; Stone, Kane; Strahan, Susan; Tilmes, Simone; Tost, Holger; Westervelt, Daniel M.; Zeng, Guang; A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1; Atmospheric Chemistry and Physics, 20, 1341-1361(2020); https://www.atmos-chem-phys.net/20/1341/2020/en_US
dc.identifier.urihttps://doi.org/10.5194/acp-20-1341-2020
dc.identifier.urihttp://hdl.handle.net/11603/17615
dc.language.isoen_USen_US
dc.publisherEGU Publicationsen_US
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Joint Center for Earth Systems Technology
dc.relation.ispartofUMBC Faculty Collection
dc.relation.ispartofUMBC Physics Department
dc.rightsThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
dc.rightsThis work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.*
dc.rights.urihttp://creativecommons.org/publicdomain/mark/1.0/*
dc.titleA machine learning examination of hydroxyl radical differences among model simulations for CCMI-1en_US
dc.typeTexten_US

Files

Original bundle
Now showing 1 - 2 of 2
Thumbnail Image
Name:
acp-20-1341-2020-supplement.pdf
Size:
17.57 MB
Format:
Adobe Portable Document Format
Description:
Download
Thumbnail Image
Name:
acp-20-1341-2020.pdf
Size:
9.14 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
2.56 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

UMBC Joint Center for Earth Systems Technology (JCET)
UMBC Faculty Collection
UMBC Physics Department