Question in CCTM

CMAQ
1

Hi everyone, I recently encountered a little problem in the process of learning CMAQ.
The CMAQ I used was version 5.2 in the early days, but i am recently convert to version 5.4. I have some questions while running CCTM 5.4.

  1. After compiling CCTM, I find that there is no original run_cctm.csh in scripts. Only run the case script, may I ask everyone is modified on the case script?Or how do I choose the right script case for me?
  2. At present, my idea is to run icon, bcon, mcip in version 5.2 and the output
    put into the version 5.4 CCTM . I have not tried it yet, but would like to ask if it is feasible?

I would appreciate it if anyone would help me

2

There is none of case called “right script”. You can modify any scripts under the CCTM. If you are simulating air quality over China, simply choose one then revise the settings based on your CMAQv5.2.

I guess that you will encounter errors from the MCIP in CMAQv5.2 as the upgrade of MCIP in CMAQv5.4+ is not compatible with older version of CMAQ (if I recall correctly).
I highly recommend keeping the workflow under the same version of CMAQ rather than mixing them, as the chemical mechanism and other settings (you will see BCON file fixed when running CCTM) may result in unexpected simulated outputs (which would make diagnosing the exact issue challenging).

1 Like
3

Thank you for your reply and thank you for helping me solve some confusion!
I still have a problem, i will recompile the icon, bcon, and cctm sections(eg:bldit_icon.csh) when I use new chemistry mechanics in 5.2, However, when I opened bldit_icon.csh/bldit_bcon.csh in version 5.4, there was no option to modify the chemical mechanism, which is different from 5.2. Does this mean that if i want to modify the chemical mechanism, i just need to recompile the cctm?

4

I have clarified that using old executables is not recommended and I believe that I have made this statement clear. Sometimes unexpected bugs and issues could take a while to address.

There is no need to be concerned about this in CMAQv5.4. Make sure that you choose the right file when generating ICON and BCON files.