CMIP6 Emissions Issue and Next Steps

[cecilehannay]

Issue:

• We discovered an issue with the CMIP6 emission files on the SE grid due to improper FV-to-SE interpolation. This affects all ongoing CESM development runs.
• From looking at plots: the issue might be only in the BC but it might affect other fields too.

Action Items

• Correct CMIP6 SE emissions
• Evaluate the impact of the corrected emissions in both piControl and 20th-century runs .

Detailed plan:

Correcting SE emissions:

• Orignal files in: /glade/campaign/cesm/cesmdata/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015/
• Nan will regrid the emissions files on the SE grid using conservative remapping to interpolate FV to SE grid. She will use the CESM2-LE files (including smooth BB emissions).
• Simone will provide path to original SOAE files.
• Simone will provide user_nl_cam file.

Runs

• Use the baseline 166 (b.e30_beta06.B1850C_LTso.ne30_t232_wgx3.166 #93)
  • 166 uses beta06 with the SOurceMods and user_nl from:
    /glade/campaign/cesm/cesmdata/cseg/runs/cesm2_0/b.e30_beta06.B1850C_LTso.ne30_t232_wgx3.166
• Run CESM3 piControl and 20th-century simulations with corrected CMIP6 emissions.
• Run CESM3 piControl with CMIP7 emissions in parallel.
  • Ben will provide user_nl_cam to start a piControl with CMIP7 emissions

@nanr

[islasimpson]

Here's a summary of the emissions we've been using and their differences from the original CMIP6 emissions and what we are now using as corrected emissions. "fv" is the CMIP6 emissions that were used in CESM2, "buggy" is what we have been using in CESM3 development, and "se" is what we're now using in 183 which is the "fv" emissions conservatively remapped to the se grid.

[nanr]

New regridded ne30 forcing files can be accessed here: @cecilehannay

/glade/campaign/cesm/cesmdata/cseg/inputdata/atm/cam/chem/emis/emissions_ssp370-BB_smoothed_ne30pg3 /glade/campaign/cesm/cesmdata/cseg/inputdata/atm/cam/chem/emis/CMIP6_emissions_1750_2015_ne30pg3