Articles | Volume 10, issue 2
Geosci. Model Dev., 10, 585–607, 2017

Special issue: Coupled Model Intercomparison Project Phase 6 (CMIP6) Experimental...

Geosci. Model Dev., 10, 585–607, 2017

Model experiment description paper 09 Feb 2017

Model experiment description paper | 09 Feb 2017

AerChemMIP: quantifying the effects of chemistry and aerosols in CMIP6

William J. Collins1, Jean-François Lamarque2, Michael Schulz3, Olivier Boucher4, Veronika Eyring5, Michaela I. Hegglin1, Amanda Maycock6, Gunnar Myhre7, Michael Prather8, Drew Shindell9, and Steven J. Smith10 William J. Collins et al.
  • 1Department of Meteorology, University of Reading, Reading, RG6 6BB, UK
  • 2National Center for Atmospheric Research, Boulder, CO, USA
  • 3Norwegian Meteorological Institute, Oslo, Norway
  • 4Laboratoire de Météorologie Dynamique, IPSL, Université Pierre et Marie Curie/CNRS, Paris, France
  • 5Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
  • 6School of Earth and Environment, University of Leeds, Leeds, UK
  • 7CICERO – Center for International Climate and Environmental Research Oslo, Oslo, Norway
  • 8University of California, Irvine, CA, USA
  • 9Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
  • 10Joint Global Change Research Institute, Pacific Northwest National Laboratory, 5825 University Research Court, Suite 3500, College Park, MD 20740, USA

Abstract. The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) is endorsed by the Coupled-Model Intercomparison Project 6 (CMIP6) and is designed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. These are specifically near-term climate forcers (NTCFs: methane, tropospheric ozone and aerosols, and their precursors), nitrous oxide and ozone-depleting halocarbons. The aim of AerChemMIP is to answer four scientific questions.

1. How have anthropogenic emissions contributed to global radiative forcing and affected regional climate over the historical period?

2. How might future policies (on climate, air quality and land use) affect the abundances of NTCFs and their climate impacts?

3.How do uncertainties in historical NTCF emissions affect radiative forcing estimates?

4. How important are climate feedbacks to natural NTCF emissions, atmospheric composition, and radiative effects?

These questions will be addressed through targeted simulations with CMIP6 climate models that include an interactive representation of tropospheric aerosols and atmospheric chemistry. These simulations build on the CMIP6 Diagnostic, Evaluation and Characterization of Klima (DECK) experiments, the CMIP6 historical simulations, and future projections performed elsewhere in CMIP6, allowing the contributions from aerosols and/or chemistry to be quantified. Specific diagnostics are requested as part of the CMIP6 data request to highlight the chemical composition of the atmosphere, to evaluate the performance of the models, and to understand differences in behaviour between them.

Short summary
We have designed a set of climate model experiments called the Aerosol Chemistry Model Intercomparison Project (AerChemMIP). These are designed to quantify the climate and air quality impacts of aerosols and chemically reactive gases in the climate models that are used to simulate past and future climate. We hope that many climate modelling centres will choose to run these experiments to help understand the contribution of aerosols and chemistry to climate change.