Negative values in concentrations

[nikhil korhale]

Hi 

I am running the WRF-Chem model using ECMWF meteorological data, CAMS emissions inventory, and WACCM IC/BC data.

I am using the chem_opt = 202 option, but I am getting negative values in concentrations and seeing artifacts in the output.

Interestingly, the chem_opt = 201 option works fine.

I have checked all the input and emissions files—there are no negative values in them.

Can anyone please help me resolve this issue? I am attaching the namelist.input file.

Thank you in advance

Best regards

Nikhil Korhale

[Mary Barth]

Nikhil,

Thanks for checking the input and emissions file as well as trying a run with chem_option = 201. 

For chem_option = 202, do you have the cloud chemistry turned on? If so, try a run with it turned off and see if that removes the negative values. As far as I know, the solver shouldn't be creating negative values and there are places where positive definite values are checked.

Another idea: Are you using using chem_adv_opt   = 2 ?

Mary

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Mary Barth 

Senior Scientist   

phone: 303-497-8186    email: bar...@ucar.edu

NSF - National Center for Atmospheric Research

P.O. Box 3000

Boulder, CO 80307

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