~~ODT~~ ~~DISCUSSION:closed~~   //Go to =>// [ [[pmip3:design:pi:index|PI]] ] - [ [[pmip3:design:6k:index|6ka]] ] - [ [[pmip3:design:21k:index|21ka]] ] - [ [[pmip3:design:lm:index|LM]] ]- [ **8.2ka** ] - [ [[pmip3:design:li:index|LI]] ] - [ [[pmip3:design:plio:index|Plio]] ] ====== 8.2ka Experimental Design ====== **Page in progress**: this is not the final version!\\ \\ Use the [[index#page_bottom_tag|discussion]] panel at the end of the page for comments Information about metadata and variables to be contributed can be found here: {{:pmip3:docs:8k-variables.xlsx|}} ===== Boundary conditions ===== The following are ideal boundary conditions, but experiments that deviate from these boundary conditions may also be contributed if complete metadata are provided. ==== Summary of 8.2ka boundary conditions ==== Boundary conditions below are for 8.5 ka (i.e. before lake drainage) ^ ^ PMIP3/CMIP5 ^ Minimum solution ^ | Orbital parameters | [ **ecc** = 0.19199 ] - [ **obl** = 24.222° ] - [ **peri-180°** = 319.495° ] | | | Date of vernal equinox | March 21 at noon | | | Trace gases | [ **CO2** = 260 ppm ] - [ **CH4** = 660 ppb ] - [ **N2O** = 260 ppb ] - [ **CFC** = xxx ] - [ **O3** = same as PI ] | | | Aerosols | Same as PI | | | | | | | Solar constant | As in PI | | | Vegetation | prescribed or interactive as in CMIP5 PI | | | Ice sheets | Remnant Laurentide ice-sheet (provided*) | Same as PI | | Topography and coastlines | Modification of Hudson Bay coastlines (provided*) | Same as PI | *For the ice-sheet reconstruction, see discussion on LGM wiki page Please use the [[index#page_bottom_tag|discussion]] panel to **comment** this table! ==== Freshwater forcing ==== Two different types of freshwater forcing: the background melt-flux from the Laurentide Icesheet, and the Lake Agassiz drainage. The former supposedly prevented Labrador Sea deep convection (see Hillaire-Marcel et al. 2006 GRL) **Proposed Background Early Holocene melt-water forcing** (mandatory) | Flux | 0.05 Sv over 500 years | | Location | Either part or all of the Labrador Sea (up to the individual modeling groups, as long as it is not added outside the Labrador Sea)| **Proposed Lake Agassiz drainage** (mandatory): | Flux | 2.5 Sv over 1 year | | Location | Either part or all of the Labrador Sea (up to the individual modeling groups, as long as it is not added outside the Labrador Sea)| | Ensemble | this experiment should be completed at least three times, beginning at different years in the control simulation| | Duration | experiment should be integrated until the AMOC recovers, except in the case of unrealistically long (i.e., multicentury) recoveries| ==== 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 are forced by CO2 concentrations. Please use the same protocol as in CMIP5 to store the carbon fluxes and the variables needed for PCMIP (see list here) ==== 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]]) ===== Initial conditions ===== ^ ^ PMIP3 ^ Alternative solution ^ | Initial conditions | Branch off PI after adjustement | Same as in PI | | Model spin up | Same as in PI | | \\ \\ \\ ---- [ [[pmip3:|PMIP3 Wiki Home]] ] - [ [[pmip3:wiki_help|Help!]] ] - [ [[wiki:syntax|Wiki syntax]] ]   - [ [[index#page_top_tag|Top]] ]