CAM6 bulk aerosols

[TCNasa]

Can anyone suggest a simple way to make CAM6 use the bulk aerosol model?

 

[cacraig]

There is a CAM namelist (which can be seen at: CESM2 CAM6.3 Namelist Definitions) called prescribed_aero_model. The values for it are 'bulk' and 'modal'.

If your question is more complicated than this, please open a new post in the CAM-Chem forum as aerosols are handled by them.

 

[TCNasa]

Thanks for your help. I've been trying to understand how to implement namelist variables. My documentation may be out of date. How do I get this variable into the input namelist?

 

[TCNasa]

Ok. I can change namelist variables in user_nl_cam, but I can't find the namelist camexp which contains prescribed_aero_model?

 

[cacraig]

If you add:

prescribed_aero_model = 'bulk'

to your user_nl_cam, the camexp namelist section should appear in your atm_in file automatically. Let me know if it does not.

 

[TCNasa]

I tried that but it doesn't show up in the atm_in file

 

[cacraig]

What version of CESM or CAM have you checked out? What is your create_newcase command that you are using? With that information, I can try to debug what might be going on. If it is not readily apparent, I'll move this over the CAM-Chem as there may be a dependency of which I'm not aware.

 

[TCNasa]

./create_newcase --case cam6f2000 --compset F2000climo --res f09_f09_mg17

And adding the "bulk" statement to the user_nl_cam file in the case subpath

I think it's CESM 2.0 which can process CAM6 but I'm having trouble verifying this.

 

[cacraig]

Do a `git status` while sitting in the main directory and let me know what it says. If that doesn't work, please look at the top of CAM's doc/ChangeLog and let me know what version it says.

 

[TCNasa]

git status didn't work. it complained about it not being a git repository. I copied from someone else here locally.
The ChangeLog file says cesm2.1.3-rc.01 . March 5, 2020

 

[cacraig]

I have confirmed that I too am unable to set this namelist using the F2000climo compset. This indicates to me that it is more complicated than just setting the namelist option. As a result, I am moving this to the CAM-Chem forum as they will be able to help you get set up correctly.

 

[TCNasa]

Thanks for trying

 

[fvitt]

Try this:

./xmlchange -append CAM_CONFIG_OPTS="-chem none"

This will force the CAM to use prescribed bulk aerosols. In some versions of CESM this did not work correctly. If this does not work for you, let me know what version you are using.

 

[TCNasa]

I tried that but it caused a crash after case.submit:
ERROR: chem_surfvals_readnl:: ERROR reading namelist

I should mention I removed the earlier change to my user_nl_cam file.

CESM 2.1.3

 

[tilmes]

The bulk aerosol model is not supported in CAM6, and therefore there are very likely various problems to get this to run.
However you should be able to run this in CAM4.
Simone