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Cloud radiation input necessary to run PORT

Hi all,

I am trying to use PORT (with CAM4) to understand the radiative impact of clouds in a warmer-than-modern-day climate.
I ran a base case following the user guide and got the input data (cam.h1 files from base run) that's necessary to run PORT.

My ultimate goal is to find the changes in TOA and surface radiation due to clouds in the warmer climate. From what I understood, I need to change the radiation inputs that deal with cloud properties from the perturbation run in PORT. To do that, I assume I need to change all the cloud radiation inputs including cloud fraction. However, I don't know what some of the radition inputs actually mean (the long_name just says "radiation input: cloud property")

Can anyone please confirm if I'm considering the correct variables here and what are the corresponding output variable from CAM for the remaining variables:

input variable in h1 file from PORT - corresponding CAM output variable
rad_cicewp (radiation input: cloud property) - ??
rad_cld (radiation input: cloud fraction) - CLOUD
rad_cldemis (radiation input: cloud property) - (EMIS?)
rad_cldtau (radiation input: cloud property) - ??
rad_cliqwp (radiation input: cloud property) - ??
rad_watice (radiation input: cloud ice) - CLDICE
rad_watliq (radiation input: cloud liquid water) - CLDLIQ

Probably rad_cicewp, rad_cldtau and rad_cliqwp are cloud ice water path, optical depth and liquid water path. But I don't know what are the corresponding output variables from CAM.

Thank you so much,


New Member
It has been a while since I've looked at this, so I hope I'm not misleading you on the following.
cldemis is cloud emissivity
cicewp is cloud ice water path
cldtau is shortwave cloud optical depth
cliqwp is the cloud liquid water path

The output names are created if you use some namelist like rad_data_output=.true. (or at least it was something like that for CAM4).
I don't know if PORT works with CAM 4.

I hope this helps.