Model Intercomparison Project
| Attribute | Value |
|---|---|
| mip_abstract | The 15th Jan 2022 Hunga-Tonga eruption is causing a very-different volcanic forcing than Pinatubo & El Chichon, with only a modest ~0.5Tg emission of SO2 but also ~150Tg of water vapour emitted deep into the stratosphere (Carn et al., 2022; Millan et al., 2022) . The resulting enhancement to stratospheric water vapour (sWV) was quantified by Jenkins et al. (2023, Nature Climate Change) to have a +0.12 W/m2 radiative forcing, with tangible impact on near-term climate projections , and factored-in to the May 2023 IPCC-methods "2022 Climate Indicators" analysis (Forster et al., 2023a, 2023b), the 1st of a series of annual updates to the August 2021 IPCC AR6 WG1 report (chapter 7, Forster et al., 2021). The eruption is suggested to be the first observed-case of a net surface warming eruption (Sellitto et al., 2022), the positive radiative forcing from elevated stratospheric water vapour exceeding the negative radiative forcing from volc-aerosol, even with the unexpectedly strong aerosol signal (e.g. Khaykin et al., 2022). The new CMIP7-VolMIP Duo-Forcer experiment (proposed in April 2023 at the EGU splinter group) will be a climate-response experiment similar to the CMIP6-VolMIP Volc-Pinatubo-Full with each ESM using common prescribed volcanic forcing datasets to enact the same radiative forcing from datasets provided to each CMIP7 model. For the Volc-Pinatubo-Full experiment for CMIP6 models applied the 1991-1994 post-Pinatubo period of the CMIP6 stratospheric aerosol dataset, and for the Volc-DuoForcer-Full experiment for CMIP7, an equivalent waveband-mapped volcanic-aerosol dataset will be provided to the models for the "major phreato-Plinian forcing", but with also a volcanic-sWV dataset provided as well, to enact also a stronge positive above-cloud volcanic forcing, similar to Hunga-Tonga, but scaled-up in magnitude. The specifics of the volcanic aerosol and volcanic sWV datasets for the experiment remain to be determined, but the plan proposed at EGU was to apply a scaled-up version of the Hunga-Tonga observed SWV & aerosol for 24-months 2022-2023, combined with a projection for the SWV & aerosol for the period 2024-2031. The suggested protocols for this CMIP7 volc-DuoForc-full experiment will broadly follow those from the CMIP6 volc-Pinatubo-full experiment, with the volcanic aerosol & sWC forcing datasets enacted from the Pre-Industrial Control experiment with a specific sampling protocol, potentially to match the same 27-member ensemble run for CMIP6-volc-pinatubo-full with 3 ensemble members in each of 9 ENSO-NAO sectors (warm/neutral/cold-ENSO & positive/neutral/negative-NAO), but models to run for 10-years to ensure complete through sWV residence time in the stratosphere. The design is likely then to have sensitivity experiments with volc-SWV-only and volc-aerosol-only (volc-DuoForc-SwvOnly and volc-DuoForc-AerOnly. In summary, the new CMIP7-VolMIP DuoForcer experiment will compare ESM simulated climate-response to common major phreato-Plinian volcanic forcing, with scaled-up Hunga-Tonga SWV & aerosol “duo volcanic forcing”. The experiment will enable to compare each ESM's “volcano-climate sensitivity” (VCS) in this combined sWV and aerosol case, compared to the CMIP6 volc-Pinatubo-full experiment where little spread in VCS was seen for that SW-dominant above-cloud Pinatubo-climate-response experiment. References: Carn_et_al_2022: https://doi.org/10.3389/feart.2022.976962 Forster_et_al_2021: https://doi.org/10.1017/9781009157896.009 Forster_et_al_2023a: https://doi.org/10.5194/essd-15-2295-2023 Forster_et_al_2023b: https://doi.org/10.5194/essd-15-2295-2023-supplement Jenkins_et_al_2023: https://doi.org/10.1038/s41558-022-01568-2 Khaykin_et_al_2022: https://doi.org/10.1038/s43247-022-00652-x Millan_et_al_2022: https://doi.org/10.1038/s43247-022-00652-x Sellitto_et_al_2022: https://doi.org/10.1038/s43247-022-00618-z Zanchettin_et_al_2022: https://doi.org/10.5194/gmd-15-2265-2022 |
| mip_long_name | Joint Hunga-Tonga-MIP and VolMIP "DuoForcer" major phreato-Plinian forced-response experiment |
| mip_website | https://www.sparc-climate.org/activities/hunga-tonga/ |
| name | HT-MIP/VolMIP |
| uid | 527f5c7c-8c97-11ef-944e-41a8eb05f654 |