Where I can find the surf emission or LBCs for CFC-12 and CFC-11?

[howard@earth_northwestern_edu]

Hello all,

I was wondering if any of you could help point me towards the files containing the data for either the surf emission or lower boundary conditions for CFC-12 and CFC-11.

Thanks for your help!!

 

[nusbaume]

Hi Howard,

You can find the CFC-11 and CFC-12 forcings for a given CAM or CESM run by looking in the atm_in file in your run directory (which if you don't have it can be generated by running preview_namelists in your case directory). In that file you can search for "CFC", which should either be in the chem_surfvals_nl group, where the flbc_file is what contains the data for the surface values, or in the chem_inparm group, where it should point to the file that is providing either the surface emissions (srf_emis_specifier) or the 3-D "emissions" (ext_frc_specifier).

Please note that which option the model is using will likely vary depending on the chemistry package that was chosen.

Anyways, I hope that helps, and have a great day!

Jesse

 

[howard@earth_northwestern_edu]

Hi Jesse,

Thank you so much. That was very helpful! I found them in the LBC file LBC_1765-2005_1.9x2.5_CMIP5_za_c091204.nc.

I was wondering if you have an idea of where I could find the default 2000 Earth emission for those two species within the input file directory here: https://svn-ccsm-inputdata.cgd.ucar.edu/trunk/inputdata/atm/? The IPCC emission files under atm/cam/chem/ don't have any CFCs.


Thanks again!

-Howard

 

[nusbaume]

Hi Howard,

I suspect the precise data file for CFCs will depend on the model configuration you are running (which is why looking inside atm_in is always a good idea). However, for an F2000 compset I have it looks like the CFC lower boundary conditions are being pulled from here:

https://svn-ccsm-inputdata.cgd.ucar.edu/trunk/inputdata/atm/waccm/lb/LBC_2000climo_CMIP6_0p5degLat_c180227.nc

Hope that helps, and have a great day!

Jesse