Create MAM5 no-chemistry compsets FHIST (58L and 93L) (related to issue #663)

[tilmes]

What is the feature/what would you like to discuss?

While for chemistry compsets we need to add the MAM5 modal model version into the workhorse model, the no-chemistry versions do not need to add the additional 5th mode, which is the new coarse model sulfate mode for the stratosphere. This is because stratospheric aerosols are prescribed in CAM (without chemistry). However, in order to be consistent between the chemistry and no-chemistry version, we have to adjust the log normal standard deviation for each mode to be the same in both. This change is desired for improved representations of sea-salt and dust in both chemistry and no-chemistry model versions.

Is there anyone in particular you want to be part of this conversation?

@fvitt @adamrher @ce

Will this change (regression test) answers?

Yes

Will you be implementing this enhancement yourself?

No

[fvitt]

@tilmes, Is this MAM4 with the physprops files used in CAMchem-MAM5? If I understand correctly, the "log normal standard deviation for each mode" is the mode width, or sigma, which is read in from the physprop file. Correct?

[tilmes]

@fvitt Yes that is correct, in order to change the sigma values, we have to change the physprop files in the namelists.

[fvitt]

@tilmes Please confirm that these are the correct physprops files that you would like to switch MAM4 to:

'M:mam4_mode1:/glade/p/cesmdata/cseg/inputdata/atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_sig1.6_dgnh.48_c140304.nc',
'M:mam4_mode2:/glade/p/cesmdata/cseg/inputdata/atm/cam/physprops/mam4_mode2_rrtmg_aitkendust_c141106.nc',
'M:mam4_mode3:/glade/p/cesmdata/cseg/inputdata/atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_c141106.nc',
'M:mam4_mode4:/glade/p/cesmdata/cseg/inputdata/atm/cam/physprops/mam4_mode4_rrtmg_c130628.nc'

[tilmes]

[tilmes]

Here is a view of MAM5 changes with chemistry. Therefore, in addition to changing the sigma values for the coarse mode only, we also have to change the size range back to those in CAM5 for the coarse mode, which is 1-4mircons (via the plot above)

[fvitt]

I am not seeing where the size ranges are set in the code.

[fvitt]

The size ranges are in physprops files in addition to the sigmas. So using the CAM5 (MAM3) coarse mode physprop file should be sufficient.