evolving-CO2-in-ExoCAM

Here are Fortran source files used in the paper, "Evolving CO2 rather than SST leads to a factor of ten decrease in GCM convergence time". These source files should be used with ExoCAM.

Requirements

You need to know how to run ExoCAM aqua-planet simulations (E2000C4AQN or E2000C4AQI) with sea ice turned off.

Usage

First, create an ExoCAM aqua-planet case (E2000C4AQN or E2000C4AQI, referred to as "${EXOCAM_CASE}").

Second, turn off sea ice by decreasing the freezing point of sea water (SHR_CONST_TKFRZSW in SourceMods/src.share/shr_const_mod.F90).

Third, copy SourceMods to the case. In this process, some files are overwritten.

$ cp -Ryv SourceMods "${EXOCAM_CASE}"

Fourth, change parameters. The global-mean SST is sst_expct in SourceMods/src.docn/docn_comp_mod.F90. The CO2 e-folding timescale is efld_time in SourceMods/src.cam/prog_mod.F90.

Finally, build and run the simulation.

The evolution of CO2 only shows in the log file of the atmosphere model. We use get_co2.py to collect the CO2 data in the log file and create an NetCDF file for each simulation.

License

MIT