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PM 2.5 Dry calculations - MOSIAC scheme

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New member
Dear all,

Please could you help me with calculations from the wrf outs?
I wonder how can I use PM2.5 dry from chem option 201 to compare with ground obvs data?
Do I need to add the component bins (a01 to a03 ) to get the water component to the PM2.5? How can I add water component to the pom2.5 diagnostic in the wrfout files?

Please help me

Hi Lin,

Depending on what ground site data you are referring to, you should be able to directly compare modeled PM2_5_DRY to ground station data. Most ground PM data report the dry weight (or something at ~30% RH, which would not result in hygroscopic growth). Check with the data reporting to make sure. If you need the aerosol water content, you can do two things:

1. If you haven't yet run your simulations, add PM_2_5_WATER to your output history by using the my_iofields file/namelist option.
2. Use water_ao{1..4} - here you will need to multiple by air density since the units are ug/kg.