CAM5 aerosol direct effect calcultaion

[yangyangiap@gmail_com]

HI
I want to use cam5 to calculate the aerosol direct effect.
First I modified the radiation.F90(rrtmg), so that aerosols can not affect the climate.
But I don't know how to reduce the affection of the aerosol indirect effect, so I try to set the variables, naai, npccn and nacon,in stratiform.F90 to 0.
Is it right?
If it is wrong, how can I calculate the direct effect.
Thank you!

 

[lupeng2006@hotmail_com]

maybe you can use RK scheme instead MG scheme, for RK scheme can not include aerosol indirect effect

 

[hannay]

You can estimate the direct effect of aerosols by performing 2 CAM simulations:
- one simulation with the present-day aerosol emissions
- one simulation with the pre-industrial emissions
all the other forcings being kept constant (greenhouse gases, solar insulation, ozone, ...)
Then you can compute the direct effect by looking at the difference between the FSNTC in the 2 simulations (where FSNTC is the net clear-sky shortwave radiation fluxes at the top of teh model)

 

[CESM researcher]

HI
I want to use cam5 to calculate the aerosol direct effect.
First I modified the radiation.F90(rrtmg), so that aerosols can not affect the climate.
But I don't know how to reduce the affection of the aerosol indirect effect, so I try to set the variables, naai, npccn and nacon,in stratiform.F90 to 0.
Is it right?
If it is wrong, how can I calculate the direct effect.
Thank you!

Hi
I don't know how to reduce the affection of the aerosol indirect effect,Can you could give me some guidance

 

[yinjiyuan]

You can estimate the direct effect of aerosols by performing 2 CAM simulations:
- one simulation with the present-day aerosol emissions
- one simulation with the pre-industrial emissions
all the other forcings being kept constant (greenhouse gases, solar insulation, ozone, ...)
Then you can compute the direct effect by looking at the difference between the FSNTC in the 2 simulations (where FSNTC is the net clear-sky shortwave radiation fluxes at the top of teh model)

Hi! May I ask What should I do if I want to calculate the direct effect of aerosols on precipitation?