Anthropogenic and Natural Radiative ForcingAnthropogenic and Natural Radiative Forcing
VolMIP is a protocol-driven international project aiming at coordinating the
activities of different Research Institutes involved in numerical climate
modelling focused on a multi-model assessment of climate models'
performance under strong volcanic forcing conditions.

VolMIP is motivated by the large uncertainties regarding the climatic responses to strong
volcaniceruptions identified in CMIP5 simulations with respect to, e.g., the radiative forcing
during periods of strong volcanic activity (e.g., Santer et al., 2014; Marotzke and Forster, 2015),
the Northern Hemisphere's winter response (e.g., Driscoll et al., 2012), the precipitation
response (Iles and Hegerl, 2014) and the response of the oceanic thermohaline circulation
(Ding et al., 2014), and by the apparent mismatch between simulated and reconstructed
post-eruption surface cooling for volcanic eruptions during the last millennium (Mann et al.,
2012, 2013; Anchukaitis et al., 2012; D'Arrigo et al., 2013; Schurer et al., 2013). Inter-model
differences are likely related to differences in the prescribed volcanic aerosol forcing data used
by different models, or variations in implementation, which create differences in the radiative
forcing produced by the volcanic aerosol forcing. The use by some modeling groups of coupled
aerosol modules for the CMIP6 historical experiments, with volcanic forcing thereby explicitly
simulated based on estimates of SO2 emissions (Gettelman et al.,  pers. comm., 2015), will
increase inter-model spread in volcanic forcing.

Therefore, VolMIP fills the need for a coordinated model intercomparison with volcanic forcing
- in terms of aerosols optical properties - constrained across participating models. Specifically,
VolMIP will assess to what extent responses of the coupled ocean-atmosphere system to the
same applied strong volcanic forcing are robustly simulated across state-of-the-art coupled
climate models and identify the causes that limit robust simulated behavior, especially differen-
ces in their treatment of physical processes. VolMIP has defined two sets of experiments:
the first focuses on the short-term atmospheric response; the second focuses on the long-term
response of the coupled ocean-atmosphere system (Zanchettin et al., 2012)

Anchukaitis K, et al. (2012) Tree-rings and volcanic cooling. Nature Geoscience, 5: 836-837,

D'Arrigo, R., Wilson, R., & Anchukaitis, K. J. (2013) Volcanic cooling signal in tree ring temper-
ature records for the past millennium. J. Geophys. Res. Atmosph., 118(16), 9000-9010

Ding, Y., et al. (2014) Ocean response to volcanic eruptions in Coupled Model Intercomparison

Project 5 (CMIP5) simulations. J. Geophys. Res., 119, 5622-5637, doi:10.1002/2013JC009780

Driscoll, S., et al. (2012) Coupled Model Intercomparison Project 5 (CMIP5) simulations of
climate following volcanic eruptions. J. Geophys. Res. Atmosph., 117, D17105,

Iles C. and Hegerl G.C. (2014) The global precipitation response to volcanic eruptions in the
CMIP5 models. Environm. Res. Lett., 9, 104012

Mann, M.E., Fuentes, J.D., Rutherford, S. (2012) Underestimation of volcanic cooling in tree-
ring based reconstructions of hemispheric temperatures. Nature Geosc., doi:10.1038/ngeo1394

Marotzke, J., and Forster, P. M. (2015) Forcing, feedback and internal variability in global
temperature trends. Nature, 517, 565-570. doi:10.1038/nature14117

Santer, B. D. et al.
(2014) Volcanic contribution to decadal changes in tropospheric temperature.
Nature Geosc., 7(3), 185-189, doi:10.1038/ngeo2098

Schurer, A., Hegerl, G.C., Mann, M., Tett, S.F.B., Phipps, S (2013) Separating forced from
chaotic variability over the last millennium.
J. Climate, doi:10.1175/JCLI-D-12-00826.1

Zanchettin, D., et al. (2012), Bi-decadal variability excited in the coupled ocean–atmosphere
system by strong tropical volcanic eruptions. Clim. Dyn., 39:1-2, 419-444

Old news
17 August 2016: the GMD paper
 is published!


An update on VolMIP activities will be presented
in the MIP Session on Tuesday 20th October at
the Workshop on CMIP5 Model Analysis and
Scientific Plans for CMIP6

VolMIP at the ocean2k workshop
An occasion to discuss VolMIP on October 6-8
in Barcelona, with focus on reconstructed past
ocean variability

VolMIP at IUGG 2015
Solicited oral contribution:"Towards a coordinated
modeling assessment of the climate response to
strong volcanic eruptions" in symposium: VS32
Weather and Climate Effects of Volcanic Eruptions
(VS32/VS33)on 29 June 2015(room Club)

Definition of the volcanic forcing
input for volc-long-eq
Myriam Khodri is leading a coordinated assess-
ment of radiative forcing uncertainties for
volc-long-eq (Tambora-like experiment) using
aerosol climate models. More information is
available here.

Oral contribution: "Effect of large volcanic erupt-
ions on climate variability from inter-annual to
decadal timescales: Towards a coordinated
modeling assessment"
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Vulcano Parinacota (Chile)
Model Intercomparison Project on the climatic response to Volcanic forcing
Copyright C 2015 by Davide Zanchettin  .  All Rights reserved  .  E-Mail: