How to run CAM5 with MAM3 using emission files for MAM4?

[T_ying]

Hi everyone,
I'm trying to perform a set of experiments testing the climate response to changes of aerosols with CAM5 using MAM-3, and I'm wondering if it is possible to run MAM-3 using the CMIP6 emission files, which are suitable for MAM-4. I've noticed that in MAM-3 the black carbon and organic carbon aerosols are merged into Aitken and accumulation mode, while in MAM-4 they are treated as an additional mode. Is it possible to run MAM-3 directly with the emission of bc and oc for MAM-4 by setting them into the other two modes? Thanks.
Btw, the user_nl_cam file is set this way:

 

[T_ying]

The format of CMIP6 and AR5 emissions are basically the same, except that there's an additional variable 'time' in CMIP6 emission that counts for the number of days since 1750-01-01. Another variable 'date' is in the unit 'YYYYMMDD', which is the same in both CMIP6 and AR5 emissions. I've tried to run the case with the settings above, but it failed because the cyclical year couldn't be found. What can I do to solve this problem? Thanks~

 

[T_ying]

The format of CMIP6 and AR5 emissions are basically the same, except that there's an additional variable 'time' in CMIP6 emission that counts for the number of days since 1750-01-01. Another variable 'date' is in the unit 'YYYYMMDD', which is the same in both CMIP6 and AR5 emissions. I've tried to run the case with the settings above, but it failed because the cyclical year couldn't be found. What can I do to solve this problem? Thanks~

To whom it may concern, this problem has been fixed that I forgot to add the srf_emis_cycle_yr in the user_nl_cam file, but the first question is still to be solved. My guess is that, if the number concentrations of black carbon and primary organic carbon are not changed when they are merged into Aitken mode, then it is reasonable to do so. Is there any dfferences between the num_bc_a4 for MAM4 and the num_bc_a1 for MAM3?