Tracking OH changes in simulations

[fang159753]

Your name

fangjiong

Your affiliation

shanghai university

Please provide a clear and concise description of your question or discussion topic.

I'm new to using GEOS-Chem and have encountered some issues during actual operation.
I ran simulations by combining fullchemistry with CH4 chemistry. First, I obtained SpeciesConcVV_OH and OHconcAfterChem from the full-chemistry run. In the metrics.py script, I used the LossOHbyCH4columnTrop variable to calculate CH4 lifetime. I'm curious to know if the OH referenced in LossOHbyCH4columnTrop corresponds to SpeciesConcVV_OH, OHconcAfterChem, or another variable?

In fullchem_mod.F90, I found that LossOHbyCH4 = LossOHbyCH4 + ( Ktrop * OHconc_mcm3 * airMass_m ), where OHconc_mcm3 = State_Chm%Species(id_OH)%Conc(I,J,L). However, I'm not sure which OH variable in which file State_Chm%Species(id_OH)%Conc(I,J,L) refers to.

Additionally, when I use SpeciesConcVV_OH from the fullchemistry simulation as input for CH4 chemistry, should I look at OHconcAfterChem for the OH output? Interestingly, I’ve noticed that OHconcAfterChem values are higher than either SpeciesConcVV_OH or OHconcAfterChem obtained in full-chemistry. Could you help me understand where I might have gone wrong?

Your help would be greatly appreciated! Thank you so much!