Bug causing unrealistic sulfate levels in MOZART-MOSAIC

[Rajesh Kumar]

Hi all,

We have found unrealistically high values of sulfate in versions 4.0 and greater in some of our runs and found that it is related to fire emissions. ebu_in_sulf and ebu_sulf are not even a part of the biomass_burn_opt = 2. ebu_in_sulf is a part of biomass_burn_opt = 1 but even for that I found that transfer of ebu_in_sulf to ebu_sulf was commented out in module_plumerise1.F. This means that sulfate emissions from biomass burning are not even subjected to plumerise. So, ebu_sulf conversion to SO4 must be based on some random initialized values of ebu_sulf.

To solve this issue, we recommend commenting out ebu_sulf related entries in module_plumerise.F and set aem_so4 = 0 for biomass burning emissions in module_mosaic_addemiss.F. Some other species especially ebu_open, ebu_gly, and ebu_ hpald may also have similar problems for other chemical mechanisms. 

Please let us know if you have any questions. 

Rajesh (on behalf of NCAR WRF-Chem team)

--

Rajesh Kumar, Project Scientist III

Research Applications Laboratory 

National Center for Atmospheric Research 

E-mail: rku...@ucar.edu

Phone: +1-303-497-1413

Web: https://staff.ucar.edu/users/rkumar

[Lin Lu]

Hello, 

does this mean recompiling after making the changes in the mentioned modules?

Thank, Lin

[Rajesh Kumar]

Hello Lin,

Yes, you should recompile the model after this change. A ./clean -a may not be required but recommended. 

Thanks,

Rajesh