Global sensitivity analysis of chemistry-climate model budgets of tropospheric ozone and OH: exploring model diversity
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Projections of future atmospheric composition change and its impacts on air quality and climate depend heavily on chemistry–climate models that allow us to investigate the effects of changing emissions and meteorology. These models are imperfect as they rely on our understanding of the chemical, physical and dynamical processes governing atmospheric composition, on the approximations needed to represent these numerically, and on the limitations of the observations required to constrain them. Model intercomparison studies show substantial diversity in results that reflect underlying uncertainties, but little progress has been made in explaining the causes of this or in identifying the weaknesses in process understanding or representation that could lead to improved models and to better scientific understanding. Global sensitivity analysis provides a valuable method of identifying and quantifying the main causes of diversity in current models. For the first time, we apply Gaussian process emulation with three independent global chemistry-transport models to quantify the sensitivity of ozone and hydroxyl radicals (OH) to important climate-relevant variables, poorly characterised processes and uncertain emissions. We show a clear sensitivity of tropospheric ozone to atmospheric humidity and precursor emissions which is similar for the models, but find large differences between models for methane lifetime, highlighting substantial differences in the sensitivity of OH to primary and secondary production. This approach allows us to identify key areas where model improvements are required while providing valuable new insight into the processes driving tropospheric composition change.
Date Issued
2020-04-03
Date Acceptance
2020-02-21
Citation
Atmospheric Chemistry and Physics, 2020, 20 (7), pp.4047-4058
ISSN
1680-7316
Publisher
Copernicus Publications
Start Page
4047
End Page
4058
Journal / Book Title
Atmospheric Chemistry and Physics
Volume
20
Issue
7
Copyright Statement
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/).
the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/).
Sponsor
Natural Environment Research Council [2006-2012]
Natural Environment Research Council (NERC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000524058800001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
NE/N003411/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Physical Sciences
Environmental Sciences
Meteorology & Atmospheric Sciences
Environmental Sciences & Ecology
ATMOSPHERIC CHEMISTRY
AIR-QUALITY
UNCERTAINTIES
SIMULATIONS
EMULATION
EMISSIONS
IMPACT
OXIDES
Publication Status
Published
Date Publish Online
2020-04-03