Go to ⇒ [ PI ] - [ 6ka ] - [ LM ]

21ka Experimental Design

Page in progress: this is not the final version Use the discussion pannel below for comments

Boundary conditions

Summary of 21ka boundary conditions

PMIP3	Alternative solution
Orbital parameters	ecc=0.018994, obl=22.949°, peri-180°= 114.42°
Date of vernal equinox	March 21 at Noon
Trace gases	CO2 = 185 ppm, CH4 = 350 ppb, N2O = 200 ppb, CFC = 0, O3 = same as PI
Aerosols	Same as PI
Solar constant	1365W/m2	As in PI
Vegetation	Interactive	See specific note below
Ice sheet	Revised ICE5G???? (provided)
Topography and coastlines	From ???? (provided)	minimum changes (see note below)
River outflow	Modified according to a river pathway map (provided)	Same as PI
Ice sheet melting	add excess LGM freshwater (see below)	Same as PI
Mean ocean salinity	??? -1PSU everywhere ???

Vegetation

Depending on the complexity of the model used the vegetation will be either
- computed by the model
- prescribed to PI (some ESM may only compute vegetation phenology and carbon cycle)
- prescribed to 21ka vegetation reconstructed from a combination of model output and data analyses (please use the map provided here)
- Obtained from asynschonous coupling with a DVGM (Biome 4 model provided)

For Earth System Models with interactive carbone cycle

The simlations are forced by CO2 concentrations. Please use the same protocal as in CMIP5 to store the carbone fluxes and the variables needed for PCMIP (see list here)

Insolation

Note that insolation should follows PMIP requirements. Please check it carefuly using the following tables (LGM insolation tables)

River outflow

The river pathways and basins should be at least adjusted so that fresh water is conserved at the Earth's surface: care should be taken that rivers reach the ocean (due to the lower sea level at LGM, some river mouths have to be displaced towards the coast).

Ice-sheet mass balance

It is advised to ensure a closed fresh water balance at the Earth's surface: snow accumulating on the ice-sheets should be redistributed to the oceans, either globally or in the adjacent oceans.

Initial conditions

[ PMIP3 Wiki Home ] - [ Help! ] - [ Wiki syntax ]