AerChemMIP: quantifying the effects of chemistry and aerosols in CMIP6

Abstract

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 ozonedepleting halocarbons. The aim of AerChemMIP is to answer four scientific questions. 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.

The Interactive Stratospheric Aerosol Model Intercomparison Project (ISA-MIP): motivation and experimental design

“…Hence, ISA-MIP, which covers the uncertainties in the pathway from the eruption source to the volcanic radiative forcing, will complement the CMIP6 VolMIP project (Zanchettin et al, 2016), which addresses the pathway from the forcing to the climate response and the feedback by studying the uncertainties in the post-volcanic climate response to a well-defined volcanic forcing. ISA-MIP also complements the chemistry climate model initiative (CCMI; Eyring et al, 2013) and the Aerosol Comparison (AeroCom) initiative as well as the Aerosol Chemistry Model Intercomparison Project (AerChemMIP; Collins et al, 2017) as it concentrates on stratospheric aerosol which is not in the focus of all these activities.…”

The PMIP4 contribution to CMIP6 – Part 2: Two interglacials, scientific objective and experimental design for Holocene and Last Interglacial simulations

“…This will complement the suite of standalone ISMIP6 ice-sheet experiments (Nowicki et al, 2016; http://www.climate-cryosphere.org/ activities/targeted/ismip6) for the recent past and future and will add to increase our understanding of the ice-sheet sensitivity to climate changes. The PMIP4-CMIP6 midHolocene and lig127k simulations, and associated sensitivity experiments, are also relevant to analyses of sea-ice feedbacks to climate in SIMIP (Notz et al, 2016) and to assessments of the role of dust forcing by AerChemMIP (Collins et al, 2017). Beyond CMIP6, the planned PMIP4-CMIP6 interglacial simulations are relevant to the Grand Challenges set by the World Climate Research Programme (WCRP).…”

The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experiments

“…The PMIP4 single forcing experiments can be used in view of the CFMIP experiments testing the impact of uniform lowering of SSTs or CO 2 decrease (in AMIP configuration) and the connection to climate sensitivity for CO 2 increase should be made easier to analyse with these experiments. In terms of diagnostics that can be used to analyse the role of each component of the climate models in setting up the LGM climate, we also expect new studies based on diagnostics developed by the CMIP6 MIPs on the ocean (OMIP, Griffies et al, 2016;Orr et al, 2017), land surface and snow (LS3MIP, van den Hurk et al, 2016), aerosols (AerChemMIP, Collins et al, 2017), sea ice (SIMIP, Notz et al, 2016), and ice sheets (IS-MIP6, Nowicki et al, 2016). It is therefore important to keep the relevant output for these analyses, and the PMIP4 data request has been built based on the lists for these other MIPs.…”

“…Klockmann et al, 2016;Brady et al, 2013;Pausata et al, 2011). We also expect analyses of the impacts of these LGM forcings to strongly benefit from diagnostics developed by the Modelling Intercomparison Projects (MIPs) dedicated to these components and processes, such as OMIP for the ocean (Griffies et al, 2016;Orr et al, 2017), SIMIP for sea-ice processes (Notz et al, 2016), LS3MIP for the land surface (van den Hurk et al, 2016), AerChemMIP for dust (Collins et al, 2017), CFMIP for clouds (Webb et al, 2017), and RFMIP for radiative forcing diagnostics (Pincus et al, 2016).…”