Just as I quoted the setting method in the forum, why setting progn=0 is to turn off the aerosol indirect effect?

[cxyiyh]

Hi,friends,
Just as I quoted the setting method in the forum, why setting progn=0 is to turn off the aerosol indirect effect? Does this approach accurately indicate that the aerosol cloud interaction is turned off?
I just know setting progn=0 means no prognostic aerosols.

setting namelist.input for no aerosol feed back
progn = 0
ra_lw_physics = 4
ra_sw_physics = 4
chem_opt = 2
aer_ra_feedback = 0

setting namelist.input for aerosol direct effects
progn = 0
ra_lw_physics = 4
ra_sw_physics = 4
chem_opt = 2
aer_ra_feedback = 1

setting namelist.input for aerosol direct and indirect effects
progn = 1
ra_lw_physics = 4
ra_sw_physics = 4
chem_opt = 2
wetscav_onoff = 1,
cldchem_onoff = 1,
aer_ra_feedback = 1

The three figures in attachments

Another questions is setting chem_opt = 2 seems to have no aqueous phase chemistry.How do I consider the role of aqueous phase chemistry in the cloud？

Thanks to everyone who discussed and answered my questions!

Best Regards!

yours,
cxyiyh

 

[mg20280015]

excuse me,
do you know the answer of this question?
could you please share it ?
thank you!

 

[jordanschnell]

Hi,

The namelist values you have indicated are correct, however, as you note, you will need to choose a mechanism that includes aqueous phase chemistry. Please refer to either the user guide or Registry/registry.chem and search form a chem_opt that has a *_aq extension in the name.

Jordan