The CESM2 with CMIP5 forcing is a publicly available set of climate model simulations intended to disentangle the role of forcing versus model structure between CESM2 and CESM1 for pre-industrial, 20th and 21st centuries simulations.
A description of the project is available at: https://www.cesm.ucar.edu/projects/community-projects/CMIP5/
The current repository contains the model code and case setups for the CESM2-CMIP5 Forcing Experiment. It also contains the namelists for the CESM1, CESM2 and CESM2-CMIP5 experiments to allow a comparison between them.
Contents
To obtain the namelists of the CESM1, CESM2 and CESM2-CMIP5 experiments, you need to do the following
git clone https://github.com/NCAR/CESM2-CMIP5 --branch namelists namelists
To obtain the CESM code you need to do the following:
Clone the repository
git clone https://github.com/NCAR/CESM2-CMIP5 --branch cesm2-cmip5-tag cesm2-cmip5-tag
This will create a directory cesm2-cmip5-tag
in your current working directory.
Go into the created directory and check out the externals
cd cesm2-cmip5-tag ./manage_externals/checkout_externals
The case directories of the following CESM2-CMIP5 experiments are available
b.e21.B1850.f09_g17.cesm2-cmip5.001: pi-control (500 years) b.e21.BHIST.f09_g17.cesm2-cmip5.001: historical (1850-2005) b.e21.BRCP85.f09_g17.cesm2-cmip5.001: rcp85 (2006-2100) b.e21.BRCP85.f09_g17.cesm2-cmip5.101: rcp85 (2006-2100) with bugfix for num_a2
To obtain a specific case directory (for instance: b.e21.B1850.f09_g17.cesm2-cmip5.001), you need to do the following
git clone https://github.com/NCAR/CESM2-CMIP5 \ --branch b.e21.B1850.f09_g17.cesm2-cmip5.001 b.e21.B1850.f09_g17.cesm2-cmip5.001
The pi_control b.e21.B1850.f09_g17.cesm2-cmip5.001
starts as an hybrid run from:
- RUN_REFCASE=b.e21.B1850.f09_g17.CMIP6-piControl.001
- RUN_REFDATE=0501-01-01
The pi_control is 500 years.
The b.e21.B1850.f09_g17.cesm2-cmip5.001
starts as an hybrid run from the pi-control at year 250:
- RUN_REFCASE=b.e21.B1850.f09_g17.cesm2-cmip5.001
- RUN_REFDATE=0250-01-01
Due to computational constraints,
- only the first historical ensemble member b.e21.BHIST.f09_g17.cesm2-cmip5.001 runs from 1850-2005,
- the remaining members
b.e21.BHIST.f09_g17.cesm2-cmip5.002
, ...b.e21.BHIST.f09_g17.cesm2-cmip5.010
were started at 1920 from the first member with apertlim
perturbation.
The b.e21.RCP85.f09_g17.cesm2-cmip5.001
starts as an hybrid run from the historical run b.e21.BHIST.f09_g17.cesm2-cmip5.001 at year 2006:
- RUN_REFCASE=b.e21.BHIST.f09_g17.cesm2-cmip5.001
- RUN_REFDATE=2006-01-01
Similarly, ensemble 2-10 starts from:
b.e21.BHIST.f09_g17.cesm2-cmip5.002
=>b.e21.RCP85.f09_g17.cesm2-cmip5.002
- ...
b.e21.BHIST.f09_g17.cesm2-cmip5.010
=>b.e21.RCP85.f09_g17.cesm2-cmip5.010
The b.e21.RCP85.f09_g17.cesm2-cmip5.101
starts as an hybrid run from the historical run b.e21.BHIST.f09_g17.cesm2-cmip5.001 at year 2006:
- RUN_REFCASE=b.e21.BHIST.f09_g17.cesm2-cmip5.001
- RUN_REFDATE=2006-01-01
This run is similar to b.e21.RCP85.f09_g17.cesm2-cmip5.001 but includes a bugfix for the _a2
emissions aerosol emissions. The influence of the incorrect _a2 emissions on climate properties was found to be minimal.