//Go to =>// [ [[pmip3:design:pi:final|PI]] ] - [ **6ka** ] - [ [[pmip3:design:21k:final|21ka]] ] - [ [[pmip3:design:lm:final|LM]] ] & Non-CMIP5 exps: [ [[pmip3:design:li:final|LI]] ] ====== 6ka Experimental Design ====== ===== Boundary conditions ===== ==== Summary of 6ka boundary conditions ==== ^ ^ PMIP3/CMIP5 ^ | Orbital parameters | [ **ecc** = 0.018682 ] - [ **obl** = 24.105° ] - [ **peri-180°** = 0.87° ] | | Date of vernal equinox | March 21 at noon | | Trace gases | [ **CO₂** = 280 ppm ] - [ **CH₄** = 650 ppb ] - [ **N₂O** = 270 ppb ] - [ **CFC** = 0 ] - [ **O₃** = same as in CMIP5 PI ] | | Aerosols | Same as in CMIP5 PI | | Solar constant | Same as in CMIP5 PI | | Vegetation | prescribed or interactive as in CMIP5 PI | | Ice sheets | Same as in CMIP5 PI * | | Topography and coastlines | Same as in CMIP5 PI * | * Sensitivity experiments will be proposed as part of a working group to test the uncertainties due to the remnant ice-sheet. If you are interested in participating to this working group contact Pascale Braconnot ==== Vegetation ==== The vegetation should be treated as in the CMIP5 PI experiment. The reason is that in CMIP5 we test the version of the model used for future climate projections. Since OA and ESM models will be considered, depending on the model used the vegetation will be * prescribed to PI (which means both vegetation types and LAI are prescribed ) * Prescribed to PI with interactive LAI (models with interactive carbone cycle, but no vegetation dynamics) * Computed by the model (models with dynamic vegetation) ==== For Earth System Models with interactive carbon cycle ==== The simulations should be forced by the prescribed 6ka CO2 concentrations. Please use the same protocol as in CMIP5 to store the diagnostic carbon fluxes and the variables needed for PCMIP (see [[http://www.bridge.bris.ac.uk/projects/pcmip/experiments.html|pcmip Project]] and [[http://cmip-pcmdi.llnl.gov/cmip5/|CMIP5]]) ==== Insolation ==== Note that insolation should follows PMIP requirements. Please check it carefully using the following tables ([[http://pmip2.lsce.ipsl.fr/design/tables/inso_tables_6k.shtml|6ka BP insolation tables]]) Check carefully the date of the Vernal equinox, because it has implications when we compare paleo and PI seasonal cycle ==== 6ka for groups only running PMIP3 experiments ==== If you only run PMIP3 experiments we recommand that you follow CMIP5 (see {{:pmip3:docs:taylor_cmip5_dec31.pdf}}) or PMIP2 ([[http://pmip2.lsce.ipsl.fr|PMIP2 web site]]) for the PI simulation ===== Initial conditions ===== ^ ^ PMIP3 ^ Alternative solution ^ | Initial conditions | Branch off PI after adjustment | Same as in PI | | Model spin up | Same as in PI | | \\ \\ \\ ---- [ [[pmip3:|PMIP3 Wiki Home]] ] - [ [[pmip3:wiki_help|Help!]] ] - [ [[wiki:syntax|Wiki syntax]] ]   - [ [[final#page_top_tag|Top]] ]