Chemical variables are 0

[Xin Zhang]

 Hi!I'm Xin Zhang.

I'm using chem_opt=112 (MOZART Chemistry and GOCART aerosols (MOZCART) using KPP library).

After having prepared fiels of emission, I ran real.exe. Then I used ncview to check the wrfinput_d01.
However, all the chemical variables were 0, like the follwing picture:

Is there anything wrong with my namelist? Please see the attached namelist and picture of 'em_real'.

When I change chem_opt to 1, chemical variables aren't equal to 0.
Is it related to kpp?




Thanks!
Xin

[Xin Zhang]

Here are my steps to generate those emissions:

1. Run real.exe to generate wrfinput_d01, wrfinputd02 and wrfbdy_d01;
2. Generate FINN fire-emissions following the README.WRF.fire and no error is in the log;
3. Generate MEGAN biogenic-emissions following README.bio_emiss and no error in the log;
4. Generate MEIC anthropogenic-emissions （like NEI anthropogenic-emissions) successfully;
5. Generate wesely and exo_coldens data files for MOZART successfully;
6. Link all these emission files and 'ubvals_b40.20th.track1_1996-2005.nc' to the 'em_real' directory;
7. Change chem_opt=112 and run real.exe again.

Please see the attached log_files.

Thank you！

[Rajesh Kumar]

Hi Xin,

             All the chemical variables are zero because you have not prepared the initial and boundary conditions for your run yet. Please download "mozbc" from this page: https://www2.acom.ucar.edu/wrf-chem/wrf-chem-tools-community, follow the instructions in the README file to compile and run it. You will also need MOZART-4 output files that you can download from here: https://www.acom.ucar.edu/wrf-chem/mozart.shtml

After successfully running mozbc, you should see finite initial and boundary conditions in WRF files. 

Best,

Rajesh

[Xin Zhang]

Thank you for your help! It works!

I have another question:

Is this method correct?
Generating other emissions based on wrfinput which relies on chem_opt=0 and then using mozbc (after setting chem_opt=112 and running real.exe) to modify wrfinput and wrfbdy.

Besides, why are these chemical variables zero before running mozbc?

Best wishes,

Xin

[Rajesh Kumar]

Hi Xin,

 

Yes, the method is correct. When you generate wrfinput file, the "real" program uses only meteorology data that comes from the WPS. The "real" program does not have access to any chemical input data source except if you are using some mechanism (e.g. RADM2 with MADE/SORGAM) that use some idealized chemical species profiles included in WRF-Chem. MOZCART is not set-up to use idealized chemical profiles and thus all chemical variables are zero.

mozbc interfaces WRF-Chem with MOZART-4 output, and interpolates MOZART output onto the WRF-Chem domain. 

I hope this answers your questions. 

Rajesh

[Xin Zhang]

Thank you very much!!

Now, I understand the meaning of these mechanisms.

Best regards,

Xin