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Using Parallel Offline Radiative Transfer software with CAM (CESM1.2.2)

Hi all,

I'm running some idealized experiments with CESM1.2.2 to understand impact of polar stratospheric clouds in Arctic amplification in a warmer-than-modern-day climate. I'm using WACCM with CAM4 for my current project.
I need to find the radiative kernals and I am trying to use Parallel Offline Radiative Transfer (PORT) software. I was a little bit confused whether I can use PORT after reading the documentation (https://wiki.ucar.edu/display/port/PORT) (and earlier discussions in the forum) and decided to try.

I got the radiative outputs from the control run (compset: F1850W) and tried to use PORT for the outputs from this run (cam.h1 files). I created a case by using user-defined compset as follows:
create_newcase -case /g/data/y99/dd7103/CESM/case/May3_PORT_PIcontrol_useBasePIcontrol -user_compset 1850_CAM4%WCCM_PORT_SLND_SICE_SOCN_SROF_SGLC_SWAV -res f19_g16 -mach gadi

I added the PORT input, the switches for precision, output frequency etc following the wiki guidelines in the user_nl_cam.xml (Please refer to the user_nl_cam.txt). I could successfully build and submit the case. However, the output files are empty (maximum and minimum values are 0).

Since I didn't have an issue with building and submitting the case, I'm very confused why the output files are empty.
Is it because CESM 1.2.2 does not support PORT? In that case can you please suggest what are the alternatives to get the radiative kernels.

Thank you,


  • user_nl_cam.txt
    670 bytes · Views: 2


Cheryl Craig
CSEG and Liaisons
Staff member
I do not run PORT, so I am unable to give you direct guidance.

That said, the CAM User's Guide found at User's Guide to the Community Atmosphere Model CAM-5.3 describes in section 5.1.3 how to use PORT in the version you are using. I would suggest you try making a run using one of the two examples and you should get output from that run.

Looking in both examples, there is a namelist field called rad_diag_1 which you do not have, it may be that this is the missing namelist will solve your problem.

If you are still unable to get output after using this namelist, let us know and we'll see if someone who is more knowledgeable about PORT can respond back.