CH4 simulation in CMAQ

Hi all,

I want to activate CH4 simulation in CMAQ with ready emissions and ICBC files. I found there are CH4 species in the mech.def file, but not in the GC_cb05tucl_ae6_aq.nml file. What should I do? Do I need to use the CHEMMECH tool?

Additionally, does anyone know how significant the differences in concentrations are with or without OH/CH+CH4 reactions in regional simulations when the boundary conditions come from a global model?

Thank you in advance.

Please review this previous post about CH4 in CMAQ. How are background methane and emissions methane handled in CMAQ?

I have resolved by modifing F code. Thanks all.