====== Design for the mid-Holocene run======

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You will find on this page information about the experiment design for the PMIP4 [[.:mh|mid-Holocene]] experiment.

Please make sure to read the [[#Associated_publication|Associated publication]] before setting up your experiments or using the output data, and read any //how-to// sections associated with specific boundary conditions.

Get in touch with the following people if you have questions:


| [[Pascale.Braconnot@lsce.ipsl.fr|Pascale Braconnot]] | Scientific questions |
| [[Jean-Yves.Peterschmitt@lsce.ipsl.fr|Jean-Yves Peterschmitt]] | Technical questions or missing data|
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===== Associated publication =====

**The PMIP4 contribution to CMIP6 – Part 2: Two interglacials, scientific objective and experimental design for Holocene and Last Interglacial simulations**, Otto-Bliesner, B. L., Braconnot, P., Harrison, S. P., Lunt, D. J., Abe-Ouchi, A., Albani, S., Bartlein, P. J., Capron, E., Carlson, A. E., Dutton, A., Fischer, H., Goelzer, H., Govin, A., Haywood, A., Joos, F., LeGrande, A. N., Lipscomb, W. H., Lohmann, G., Mahowald, N., Nehrbass-Ahles, C., Pausata, F. S. R., Peterschmitt, J.-Y., Phipps, S. J., Renssen, H., and Zhang, Q., Geosci. Model Dev., 10, 3979-4003, [[https://doi.org/10.5194/gmd-10-3979-2017|doi:10.5194/gmd-10-3979-2017]], 2017.\\ \\ [[https://www.geosci-model-dev.net/10/3979/2017/gmd-10-3979-2017-supplement.zip|Supplement (Otto-Bliesner et al, GMD, 2017)]]
===== Specifications =====


^      ^PMIP4-CMIP6 specifications ^ 
| PMIP4-CMIP6 name | <wrap em>midHolocene</wrap> |
| Astronomical parameters  | **eccentricity** = 0.018682 \\ **obliquity** = 24.105° \\  **perihelion-180°** = 0.87°  \\  **Date of vernal equinox**  :  March 21 at noon  |  
| Trace gases  | **CO<sub>2</sub>** = 264.4 ppm \\ **CH<sub>4</sub>** = 597 ppb \\ **N<sub>2</sub>O** = 262 ppb \\ **CFC** = 0 \\ **O<sub>3</sub>** = same as in CMIP6 piControl  | 
| Solar activity | Same as in CMIP6 piControl (TSI = 1360.747 W.m-2) | 
| Ice sheets      | Same as in CMIP6 piControl  | 
| Topography and coastlines  | Same as in CMIP6 piControl  | 
| Volcanic activity | Same as in CMIP6 piControl  |
| Aerosols  | Modified sources, atmospheric concentrations or radiative forcing, depending on model complexity and model configuration used for DECK and historical experiments \\  cf. documenting papers: Otto-Bliesner et al, in prep and Kageyama et al, subm. \\ [[:data:aerosols|Access to data]]| 
| Vegetation     | Depending on model complexity and model configuration used for DECK and historical experiments: \\ Interactive vegetation **or** Interactive carbon cycle (LAI) **or** Prescribed to present-day values or mid-Holocene values computed from off-line vegetation model \\ The methodology to represent vegetation should be the same as for the CMIP6 piControl simulation  \\  cf. documenting papers: Otto-Bliesner et al, in prep and Kageyama et al, subm. |

===== Collaboration =====

  * The PMIP4-CMIP6 **midHolocene** and **lig127k** simulations are also expected to be relevant to analyses in [[http://www.climate-cryosphere.org/activities/groups/seaicemodeling/simip|SIMIP]]’s assessment of the role of sea-ice changes in climate changes and [[https://cmip.ucar.edu/aer-chem-mip|AerChemMIP]]’s assessment of the role of dust

===== Sensitivity experiments =====

==== Sensitivity to Prescribed Vegetation ====

==== Sensitivity to Prescribed Ice Sheets ====