Attribution of Stratospheric and Tropospheric Ozone Changes Between 1850 and 2014 in CMIP6 Models

Change log

jats:titleAbstract</jats:title>jats:pWe quantify the impacts of halogenated ozone‐depleting substances (ODSs), greenhouse gases (GHGs), and short‐lived ozone precursors on ozone changes between 1850 and 2014 using single‐forcing perturbation simulations from several Earth system models with interactive chemistry participating in the Coupled Model Intercomparison Project Aerosol and Chemistry Model Intercomparison Project. We present the responses of ozone to individual forcings and an attribution of changes in ozone columns and vertically resolved stratospheric and tropospheric ozone to these forcings. We find that whilst substantial ODS‐induced ozone loss dominates the stratospheric ozone changes since the 1970s, in agreement with previous studies, increases in tropospheric ozone due to increases in short‐lived ozone precursors and methane since the 1950s make increasingly important contributions to total column ozone (TCO) changes. Increases in methane also lead to substantial extra‐tropical stratospheric ozone increases. Impacts of nitrous oxide and carbon dioxide on stratospheric ozone are significant but their impacts on TCO are small overall due to several opposing factors and are also associated with large dynamical variability. The multi‐model mean (MMM) results show a clear change in the stratospheric ozone trends after 2000 due to now declining ODSs, but the trends are generally not significantly positive, except in the extra‐tropical upper stratosphere, due to relatively small changes in forcing over this period combined with large model uncertainty. Although the MMM ozone compares well with the observations, the inter‐model differences are large primarily due to the large differences in the models' representation of ODS‐induced ozone depletion.</jats:p>


Funder: New Zealand Ministry for Business, Innovation and Employment

Funder: NIWA programme CACV

Funder: New Zealand eScience Infrastructure

Funder: BEIS

Funder: Met Office and the Natural Environment Research Council

Funder: Natural Environment Research Council

Funder: National Center for Atmospheric Research

Funder: DLR space research program

Funder: Canadian Space Agency

ozone trend, CMIP6, AerChemMIP, chemistry-climate models, anthropogenic forcing, ozone depletion
Journal Title
Journal of Geophysical Research: Atmospheres
Conference Name
Journal ISSN
Volume Title
American Geophysical Union (AGU)
NERC (R8/H12/83/003)
Japan Society for the Promotion of Science KAKENHI (JP18H03363, JP18H05292, JP19K12312, JP20K04070, JP21H03582)
Environment Research and Technology Development (JPMEERF20202003, JPMEERF20205001)
Environmental Restoration and Conservation Agency of Japan (JPMXD1420318865)
Ministry of the Environment (MLIT1753)
National Science Foundation (1852977)
UK Engineering and Physical Science Research Council (EP/R01860X/1)