Encountering Issues Adding CO2 to CMAQ BCON for Initial Boundary Conditions

CMAQ CMAQ-PREP
1

I’m trying to use CMAQ to track CO2 and encountered an issue when creating initial boundary conditions with BCON. Here’s what I did:

  • Modified the NR namelist file.
  • Added CO2 concentrations for each layer in the profile.

However, when I run BCON, I get the following error:

SVMT2                   5          ppmV            
SVMT3                   5          ppmV            
SVMT4                   5          ppmV            
SVMT5                   5          ppmV            
SVMT6                   5          ppmV            
CO2                     5          ppmV            

Value for IOAPI_CHECK_HEADERS not defined; returning default:   FALSE

>>> WARNING in subroutine CHKFIL3 <<<
Inconsistent file attribute NVARS for file BNDY_CONC_1     
Value from file:        248
Value from caller:      249

*** ERROR ABORT in subroutine OPN_BC_FILE
Could not open nor create BNDY_CONC_1 file

How should I add CO2 to create a BCON file that includes CO2 background concentrations?

2

**Where can I change 248 to 249?**Thank you！

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3

Which version of BCON are you running, and which profile file did you modify? For the last few releases, BCON does not use the GC, AE, and NR namelist files as input, so modifying the NR namelist file prior to running BCON with a modified profile as input should not be necessary.

What I’m guessing is happening is that you first ran BCON with the unmodified profile file as input, and it generated an output file with 248 species. You then modified the profile file by adding CO2 and ran BCON again, without first deleting the existing output file. Since BCON creates outputs in FSUNKN3 mode, it cannot add any species to existing files and will exit with an error if the number (and name) of species requested in the new run does not match what is there in the existing file (if any). If this theory is correct, first removing the existing BCON file and then running your script again using your modified profile as input should fix the problem.

4

Hello, the problem is exactly as you described, the same situation. I’m using the latest version of CMAQ. I had previously generated a profile and didn’t delete it, so when I added the CO2 gas, it gave an error. Thank you so much, I can’t express in words how excited I am. This has been bothering me for a week. I want to express my sincerest gratitude to you once again.