Inquiry Regarding Modification of Marine Primary Organic Aerosol (POA) Calculation and Data Abbreviations

[ChenBHXMU]

Your name

Baihua Chen

Your affiliation

Xiamen University

Please provide a clear and concise description of your question or discussion topic.

Dear @yantosca,

I hope this message finds you well.

I am currently studying GEOS-Chem and am interested in modifying the calculation method for marine primary organic aerosol (POA). Could you please provide guidance on how to adjust the code for these modifications?

Additionally, I set up the calculation for marine POA when I used "./createRunDir.sh". I noticed that in the OutputDir file, there seems to be no data available for POA. Instead, I found data labeled as MOPO, MOPI, POx and PO2. Is there a guide or documentation available on the website that explains these abbreviations?

Thank you very much for your assistance.

Best regards, Baihua Chen

[yantosca]

Thanks for writing @ChenBHXMU. The species information is contained in the species_database.yml file:

MOPI:
  DD_DvzAerSnow: 0.03
  DD_F0: 0.0
  DD_Hstar: 0.0
  Density: 1300.0
  Formula: C
  FullName: Hydrophilic marine organic carbon aerosol
  Is_Advected: true
  Is_Aerosol: true
  Is_DryDep: true
  Is_WetDep: true
  MW_g: 12.01
  WD_AerScavEff: 1.0
  WD_KcScaleFac: [1.0, 0.5, 1.0]
  WD_RainoutEff: [1.0, 0.0, 1.0]
  WD_RainoutEff_Luo: [0.4, 0.0, 1.0]
MOPO:
  DD_DvzAerSnow: 0.03
  DD_F0: 0.0
  DD_Hstar: 0.0
  Density: 1300.0
  Formula: C
  FullName: Hydrophobic marine organic carbon aerosol
  Is_Advected: true
  Is_Aerosol: true
  Is_DryDep: true
  Is_WetDep: true
  MW_g: 12.01
  WD_AerScavEff: 1.0
  WD_KcScaleFac: [0.5, 0.5, 0.5]
  WD_RainoutEff: [0.0, 0.0, 0.0]
POx:
  FullName: Dummy species to track production rate of Ox
  Is_Gas: true
  MW_g: 48.00

PO2 is probably another dummy species to track the production of O2. It is not in the "out-of-the-box" run directory. Maybe someone else added that.

[ChenBHXMU]

Thank you for your efficient response and guidance once again! @yantosca

[yantosca]

You are welcome @ChenBHXMU!

[ChenBHXMU]

Dear @yantosca ,

I have some lingering questions. I found POA1 and POA2 in the species_database.yml file, but I couldn't find them in the data files within the OutputDir. I have set up the calculation for marine POA when I used "./createRunDir.sh". Additionally, I would like to modify the calculation of POA. The original calculation is described at this link: [https://wiki.seas.harvard.edu/geos-chem/index.php/Aerosol_emissions#Online_emission_of_marine_primary_organic_aerosol_.28POA.29]. However, I am not sure which file to modify and how to proceed in order to attempt to optimize the original algorithm.

Thank you very much for your assistance.

Best regards, Baihua Chen

[yantosca]

Thanks for writing @ChenBHXMU. I believe POA1 and POA2 are only activated when you are using a simulation with ComplexSOA species. I believe the marine POA simulation does not use the Complex SOA species, which is why you haven't found them in the output. I would suggest

Your question about modifying the calculation of POA is more of a science question than a coding question, and would be better addressed to the Chemistry WG co-chairs. Tagging: @barronh @luhu0 @jhaskinsPhD @kelvinb

[barronh]

I'm not familiar with how this is implemented, but given the topic I'd guess this would be an aerosols working group issue. In the current version of the code, I find references to POA1 and POA2 in aerosol_mod.F90, apm_driv_mod.F90, and carbon_mod.F90. So, If I were going to modify POA, I'd start by searching the code and reaching out to the aerosols working group.

[ChenBHXMU]

Thank you all for your help. I appreciate the information provided by everyone, and I will continue to study further. @barronh @yantosca

[yantosca]

Closing out this issue