abrupt-4xCO2

Warning

The ACCESS-ESM1.6 abrupt-4xCO2 experiment does not have a released and maintained configuration. These notes describe how the CMIP7 experiment was set up and are for reference only. If you would like to run an abrupt-4xCO2 experiment with the latest configuration updates, please create a help request on the ACCESS Hive Forum.

The abrupt-4xCO2 experiment simulates the climate under an abrupt quadrupling of atmospheric CO2 concentrations compared to the preindustrial level, and has been run for the CMIP7 abrupt-4xCO2 experiment

The experimental setup matches commit 37d5312 from the piControl configuration with changes to the prescribed CO2 mass mixing ratio and the restart file used.

Inputs

The abrupt-4xCO2 experiment uses the same input files as the piControl other than the initial conditions.

Restart

The abrupt-4xCO2 experiment uses the restart from the piControl experiment with calendar year 201.

Key settings

The increased CO2 concentration is set in the atmosphere/namelists configuration file. The following difference is shown with respect to the piControl configuration.

atmosphere/namelists

 &RUN_Radiation
 ...
- CO2_MMR= 4.3189e-04,
+ CO2_MMR= 1.72756e-03,

The values for other greenhouse gas concentrations, volcanic forcings, and the solar constant are indentical to the piControl configuration.