EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Ace in the hole or a house of cards: Will a DeCK experiment help atmospheric chemistry?

Alexander Archibald1, William Collins2, Mat Evans3, Paul Griffiths1, Fiona O'Connor4, Oliver Wild5, and Paul Young5
Alexander Archibald et al.
  • 1University of Cambridge, Department of Chemistry, Cambridge, United Kingdom of Great Britain – England, Scotland, Wales (
  • 2University of Reading Department of Meteorology Meteorology Building Whiteknights Road Earley Gate Reading RG6 6ET, UK
  • 3Department of Chemistry University of York, Heslington, York, YO10 5DD, UK
  • 4Met Office, FitzRoy Road, Exeter, EX1 3PB
  • 5Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK

 Over the past few decades the global atmospheric chemistry modelling community has collectively simulated 100000s of model years, producing petabytes of output, using increasingly complex  chemistry and aerosol schemes and higher resolution models. Yet, our understanding of key aspects of global atmospheric composition change has not evolved at the same pace as the tools we use to study it. Answers to key questions remain as uncertain now as they were two decades ago, including the strength of the methane self-feedback and the past and possible future evolution of tropospheric ozone in response to changing emissions and climate. Here, we will review the progress in understanding that has been generated in model intercomparison experiments (MIPs) from the last three IPCC assessment cycles: ACCENT (AR4), ACCMIP (AR5), and CCMI and AerChemMIP (AR6). We conclude that the aims and experimental design in these MIPs can be improved to reduce  the uncertainty in some of the outstanding questions in atmospheric chemistry. To this end  we propose a new set of experiments, specifically targeted at the atmospheric chemistry modelling community, that will go towards resolving outstanding challenges and integrate the wealth and expertise of chemistry transport and chemistry climate models. These experiments emulate the CMIP DeCK experiments and are designed to provide a continuing legacy for the community in understanding model evolution and process understanding. We aim to elicit  feedback and input into the experimental design from the community  with this presentation. 

How to cite: Archibald, A., Collins, W., Evans, M., Griffiths, P., O'Connor, F., Wild, O., and Young, P.: Ace in the hole or a house of cards: Will a DeCK experiment help atmospheric chemistry?, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9442,, 2022.