I am working on WRF_GHG, I would like to calculate dry and wet deposition in the dry and wet seasons for CO2 and CH4 gases. However, when I check the wrf output, I see that all the variables (DRY_DEP_FLUX and WET_DEP_FLUX) are zero in all the time steps.

I've attached my namelist.input link too.


What causes my mistake?

Could I possibly ask you to check it please? Do you know why I get the wrong zero values for two of those variables (DRY_DEP_FLUX and WET_DEP_FLUX)?


Well I can see one major reason the dry deposition is not working- the namelist variable for gas deposition (gas_drydep_opt) is turned off. I am not entirely sure how the wet deposition works, though my guess is that it only applies to aerosols, so you would need to turn on wet scavenging for non-zero values.

Some of the documentation implies that wet deposition only applies to certain chemical mechanisms and for certain chemicals. This is probably the reason you aren't getting any wet deposition.

  • $\begingroup$ Thanks for the response, I shall tell you that I am working with chem_opt=17(GHG: greenhouse gases option) and I put the wet scavenging for non-zero values too, but the model showed this error: "wet scav_onoff" option requires chem_opt=8,13,36 to 41,42,503,504,601,611". $\endgroup$ – sara Jun 1 at 6:10
  • $\begingroup$ then I had to put the value of "wet scav_onoff" and "cldchem_onoff" to zero value again , and put the value of gas_drydep_opt to 1. after all run the model by this condition for 24 hours. today I checked the wrf outpout files and saw that the dry_dep_flux and wet_dep_flux are zero again and understood that "gas_drydep_opt" doesn't affect dry_dep_flux values!!!. $\endgroup$ – sara Jun 1 at 6:10
  • $\begingroup$ Yes, the wet scavenging applies for aerosols (certain chemical mechanisms and certain chemicals). Admittedly I overlooked that it is WRF_GHG you are using and not WRF-Chem. But chem_opt=17 is probably the WRF-Chem tracer option which is not subject to dry deposition per page 4 of the user guide. What you are looking for is probably chem_opt=98, per page 36. Note this is not one of the options for wet scavenging, that is because scavenging is used more for aerosols. $\endgroup$ – BarocliniCplusplus Jun 1 at 14:36
  • $\begingroup$ Thank you dear BarocliniCplusplus, then I have to give up everything about dry_dep and wet_dep with this chem_opt=17or 16. Thanks for the response :) $\endgroup$ – sara Jun 2 at 19:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.