I'm trying to tune dust flux in the original WRF-Chem GOCART module by changing the current tuning constant (C=0.8D-9) in chem/chemics_init.F. I'm using option 300 (GOCART simple aerosol scheme, no ozone chemistry) and dust_opt=1 (GOCART). After performing simulations with different constants i.e., 0.2D-9, 0.5D-9, and 0.8D-9, all of these constants in terms of the dust amount (both in concentration and vertically integrated) look similar. What is the best way to properly tuned these constants? I appreciate the help.