Analytical startup ignores water species in IC file

[fvitt]

What happened?

Often it is useful to stabilize WACCM with CAM's "analytical IC" feature when starting from an interpolated IC file, especially in SE dycore configurations. When starting the model with analytical ICs, water species are ignored in IC file and water vapor is initialized to zero. This is problematic for stratospheric water vapor in WACCM.

What are the steps to reproduce the bug?

./create_newcase --compset FHISTC_WAt1ma --run-unsupported --res ne16pg3_ne16pg3_mt232 --case $CASEDIR
cd $CASEDIR
./xmlchange --append CAM_CONFIG_OPTS=-analytic_ic

Add these to user_nl_cam:

 analytic_ic_type = 'us_standard_atmosphere'

 ncdata = '/glade/work/fvitt/chem_ic/f.e30.FHISTC_WAt1ma_ne16np4_L135_cam6_4_156_beres0.15_1980-01-01_ncol_c260422.nc'
 use_topo_file = .true.
 bnd_topo = '/glade/campaign/cesm/cesmdata/inputdata/atm/cam/topo/se/ne16pg3_gmted2010_modis_bedmachine_nc3000_Laplace0200_noleak_greenlndantarcsgh30fac2.50_20250825.nc'

What CAM tag were you using?

cam6_4_173

What machine were you running CAM on?

CISL machine (e.g. cheyenne)

What compiler were you using?

Intel

Path to a case directory, if applicable

No response

Will you be addressing this bug yourself?

Yes

Extra info

I propose removing the line that skips over reading the water species from the IC input file,
here.