change ozone concentration

[khj]

Hi all,
I have a question.
I want to run compset FW2000climo. The first goal is to add and subtract 15% of the ozone and run the model. is this possible? If this is possible, thank you for guiding me.

 

[mmills]

FW2000climo is a WACCM compset with interactive chemistry. You could subtract 15% of the ozone from the initial condition, but it would come back within months during the model run, due to the interactive chemistry.

CAM and SC-WACCM (specified chemistry WACCM) are two versions of the atmosphere model that use prescribed stratospheric ozone, rather than interactive chemistry. Either of them could be run with an altered stratospheric ozone file.

 

[khj]

FW2000climo is a WACCM compset with interactive chemistry. You could subtract 15% of the ozone from the initial condition, but it would come back within months during the model run, due to the interactive chemistry.

CAM and SC-WACCM (specified chemistry WACCM) are two versions of the atmosphere model that use prescribed stratospheric ozone, rather than interactive chemistry. Either of them could be run with an altered stratospheric ozone file.

Dear Mike,
Thank you very much for your answer and guidance.
I just got acquainted with the model and I want to ask you if there is any guide according to which I can change the ozone concentration (I mean the file path, file name and parameters that need to be changed)

Best Regards

 

[mmills]

Dear Mike,
Thank you very much for your answer and guidance.
I just got acquainted with the model and I want to ask you if there is any guide according to which I can change the ozone concentration (I mean the file path, file name and parameters that need to be changed)

Best Regards

That depends on whether you want to change the initial condition in a WACCM run with interactive chemistry, or change the the prescribed ozone in CAM or SC-WACCM.

Assuming you want to use CAM or SC-WACCM, look in the atmosphere namelist file (CaseDocs/atm_in) to find pointers to the prescribed_ozone_datapath and prescribed_ozone_file, such as:

prescribed_ozone_datapath = '/glade/p/cesmdata/cseg/inputdata/atm/cam/ozone_strataero'
prescribed_ozone_file = 'ozone_strataero_WACCM_L70_zm5day_18500101-20150103_CMIP6ensAvg_c180923.nc'

You can then copy this file to one with a different name, and then apply any scaling you want to the O3 variable. Then you need to point to your new file by adding two lines to user_nl_cam in your case directory in order to modify the namelist:

prescribed_ozone_datapath = '/path/to/file'
prescribed_ozone_file = 'ozone_x0.85_strataero_WACCM_L70_zm5day_18500101-20150103_CMIP6ensAvg_c20220416.nc'

Note, that this does not apply to the FW2000climo compset, since that is a WACCM compset with interactive chemistry. If you just want to change the initial condition in WACCM, look for ncdata in atm_in, and follow a similar procedure to copy it and scale O3.

 

[khj]

That depends on whether you want to change the initial condition in a WACCM run with interactive chemistry, or change the the prescribed ozone in CAM or SC-WACCM.

Assuming you want to use CAM or SC-WACCM, look in the atmosphere namelist file (CaseDocs/atm_in) to find pointers to the prescribed_ozone_datapath and prescribed_ozone_file, such as:

prescribed_ozone_datapath = '/glade/p/cesmdata/cseg/inputdata/atm/cam/ozone_strataero'
prescribed_ozone_file = 'ozone_strataero_WACCM_L70_zm5day_18500101-20150103_CMIP6ensAvg_c180923.nc'

You can then copy this file to one with a different name, and then apply any scaling you want to the O3 variable. Then you need to point to your new file by adding two lines to user_nl_cam in your case directory in order to modify the namelist:

prescribed_ozone_datapath = '/path/to/file'
prescribed_ozone_file = 'ozone_x0.85_strataero_WACCM_L70_zm5day_18500101-20150103_CMIP6ensAvg_c20220416.nc'

Note, that this does not apply to the FW2000climo compset, since that is a WACCM compset with interactive chemistry. If you just want to change the initial condition in WACCM, look for ncdata in atm_in, and follow a similar procedure to copy it and scale O3.

Dear Mike,
Thank you very much for your help and answer.

 

[Ji-Hoon Oh]

Dear Mike,

These questions and answers have been very helpful to me, thank you.
I am currently using CESM2.1.3 version, and I want to run an experiment to reduce ozone in a specific area, is it possible to prescribe ozone concentration in 3 dimensions (lev,lat,lon) instead of zonal mean?