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how to close atmospheric chemistry in FHIST_BGC case


New Member

I am planing a long time (more than 200 years) run for FHIST_BGC case, and I find the atm takes more than 80 percent of the total run time. So, I would like to close the atmospheric chemistry to reduce run cost.

I attempt to only change the CAM_CONFIG_OPTS from "-phys cam6" to "-phys cam6 -chem none" by the xmlchange command. my main codes are as follows:

./create_newcase --compset FHIST_BGC --res f09_f09_mg17 --case ~/CESM2/scratch/FHIST_BGCnone &> FHIST_BGCnone.log
./xmlchange CAM_CONFIG_OPTS="-phys cam6 -chem none"
# or
# ./xmlchange --append CAM_CONFIG_OPTS="-chem none"

Then, some errors occured.
# in cesm.log
01: Opened existing file
01: /BIGDATA1/sysu_syli_3/CESM2/inputdata/atm/cam/ozone_strataero/ozone_strataero_W
01: ACCM_L70_zm5day_18500101-20150103_CMIP6ensAvg_c180923.nc 458752
01: NetCDF: Invalid dimension ID or name
01: NetCDF: Invalid dimension ID or name
00: WARNING: Rearr optional argument is a pio2 feature, ignored in pio1
01: ERROR: ADDFLD: VOLCANIC_m3 already on list
49: ERROR: ADDFLD: VOLCANIC_m3 already on list

# in atm.log
tuning parameters zm_convi: num_cin 1
tuning parameters zm_convi: ke 5.000000000000000E-006
tuning parameters zm_convi: no_deep_pbl F
**** ZM: DILUTE Buoyancy Calculation ****
ERROR: ADDFLD: VOLCANIC_m3 already on list

some log files will be provided for debug and trace errors, and a timing file from no closure atmospheric chemistry FHIST_BGC case will also be attached.

If you have any more effective and easy way, please tell me.

Any suggestion and help will be appreciated.


  • atm.log.txt
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  • CaseStatus.txt
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  • cesm.log.txt
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  • cesm_timing.txt
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  • cpl.log.txt
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Cheryl Craig
CSEG and Liaisons
Staff member
I am moving this to the CAM-Chem discussion group as they will be the ones to answer this question.


Sorry for the late reply. It is not a good idea to remove all the chemistry from the standard run.
First of all, the chemistry in CAM is not very expensive, second, the chemistry is required for processing aerosols, if you leave this out, your aerosols would not be correct any more.