Very high secondary organic aerosol concentrations with FINN fire emissions and MOZART+MOSAIC chemistry

[Yogesh Sathe]

Dear All,

I am trying to simulate PM2.5 over Northern India using WRF-Chem 3.9.1. I have configured domain having 9 x 9 km2 grid spacing. I am using MOZART+MOSAIC_4bins chemical mechanism (chem_opt =201), with settings specified in Users guide and relevant literature available. 

As, I am trying to quantify the impact of biomass burning emissions in the region I configured two separate runs:

1. Run 1 - Without BB emissions: It includes all other emissions viz. Anthropogenic (EDGAR), biogenic (MEGAN), dust, and Sea salt. It worked perfectly and results are comparable to observations, except biomass burning period in the region.

 

2. Run 2 - With BB emissions: I included FINN V2.0 data pre-processed using fire_emiss tool and the simulation started well. 

 

In Run 2, once fire emissions starts to appear the secondary organic aerosols (SOAA01 to SOAA04) starts to increase dramatically and reach non-physical values on each day. The values are reaching continuously over 4,00,000 to 5,00,000 ug/m3. The simulation continues to run for a period of month or so and then abruptly stops. Other variables look okay to me.

 

Has anyone encountered this problem before?

What could be the possible reasons for such high aerosol concentrations and how to fix this?

 

Any leads on this matter are highly appreciated.

 

I am herewith attaching namelist file and some screenshots.

 

[Yogesh Sathe]

Forgot to attach namelist.input in my last email. Please find it attached in this email.

Thank you.

[Mary Barth]

Hello Yogesh,

Your namelist looks okay to me. Have you checked ebu_oc in the wrfout to see if the emissions are too large too? Please also check the wrffirechemi file as well. 

If you don't have ebu_oc in the wrfout file, then you can add it via the iofields text file. 

 

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

Staff web page

SIMA Web Site

MUSICA Web Site

DC3 Web Site 

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[Alejandro Herman Delgado Peralta]

Hi Yogesh,

I understand what you mean, I also experienced the same problem with WRF-Chem and I couldn’t solve. So, I preferably ran with other chemical mechanism called MOZCART (Mozart-Gocart), which resulted in good simulation to me but without got details as we can get from Mozart-Mosaic.

Best regards,

Alejandro

On 23 Oct 2024, at 13:01, Mary Barth <bar...@ucar.edu> wrote:



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[Yogesh Sathe]

Hello Mary,

Thank you for the quick revert.

Yes, I have added ebu_oc field to my wrfout. Please find attached screenshot for same. Further, I have also attached screenshot of oc_a02 fraction from wrfout and it looks okay.

The fire emissions are consistently, observed to be higher.

Is this related to FINN version 2.5? Can using previous version like 1.5, have different effect?

OR 

is it because of some error in SOA module code?

Hello Alejandro,

Thank you for your inputs.

As per my knowledge, MOZCART does not simulate secondary organics. My modelling domain and simulation period are very much affected by secondary organics. Hence, I selected MOZART+MOSAIC. 

[Mary Barth]

Hello Yogesh,

You will get different answers for FINN2.5 and FINN1.5. The recent paper by Thongsame et al. shows this for an evaluation of PM2.5 in Thailand. 

Yet, you have a good question about whether the issue is with the SOA chemistry calculations. I don't know that part of the code very well, so cannot advise properly. 

- 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

Staff web page

SIMA Web Site

MUSICA Web Site

DC3 Web Site 

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^

[Yogesh Sathe]

Hello Mary,

Thank you so much for the guidance and sharing the research article. I could see from the article that FINNV2.5 fire emissions (especially MODIS+VIIRS) are higher compared to others.

However, in my case, that can not be the sole cause of such high PM2.5 and SOA concentrations in the domain.

I could see from a previous post in this group about very high Sulfate concentrations in top model layers. I could also see that user has also tried different settings changes, but with no success.

(https://groups.google.com/a/ucar.edu/g/wrf-chem-fire_emiss/c/hDMrN_ScWwc/m/VElIRJtxAQAJ)

Could you re-direct this or connect to some one who knows the code? If possible for you?

Regards

Yogesh