Aerosol sensitivity experiment

[yinjiyuan]

Hi, everyone! I would like to do some experiments on the climatic effects of aerosols under the conditions of 1850 using only atmospheric models.
Ctrl Group：I would like to turn off the aerosol (or chemical) module.
Branch Group：I need to open the aerosol module and added my own defined aerosol data.
Which compsets should I choose for these two experiments? How should I set the parameters and what parameters should I set in these two groups of experiments? I would appreciate it if you could give me some guidance!

 

[islas]

From what you describe it seems like it might be best to not turn off the chemistry for your ctrl but rather specify the emissions in both cases e.g., in your ctrl group specify emissions to be 1850's emissions and then in the branch specify them to be 1850's plus what you want. If you turn them off then it's a different model from our supported model to begin with and some tuning might be needed.

Aerosol emissions are controlled by the files in the CAM namelist under ext_frc_specifier and surf_emis_specifier. If you don't want to couple to an ocean then the F1850 compset may be a good starting point. You can see the files that are specifying the emissions by setting up the case and running ./preview_namelists and they will appear in ./CaseDocs/atm_in. Then you can modify those files to have the perturbation you want. Note that there are natural emissions (dust and sea salt) which I think are not specified in files but rather depend on the model state.

 

[yinjiyuan]

Thank you very much for your answer!

From what you describe it seems like it might be best to not turn off the chemistry for your ctrl but rather specify the emissions in both cases e.g., in your ctrl group specify emissions to be 1850's emissions and then in the branch specify them to be 1850's plus what you want. If you turn them off then it's a different model from our supported model to begin with and some tuning might be needed.

Aerosol emissions are controlled by the files in the CAM namelist under ext_frc_specifier and surf_emis_specifier. If you don't want to couple to an ocean then the F1850 compset may be a good starting point. You can see the files that are specifying the emissions by setting up the case and running ./preview_namelists and they will appear in ./CaseDocs/atm_in. Then you can modify those files to have the perturbation you want. Note that there are natural emissions (dust and sea salt) which I think are not specified in files but rather depend on the model state.

Thank you very much for your answer! It's very helpful! Then I have one more question. If I don't want to use aerosol emissions, but instead use a prescribed aerosol concentration (mixing ratio) , how do I change the parameters and what settings do I make? Thank you very much!