Fine Chloride (SALACL) output is highly underestimated

[ankitpatel0698]

Your name

Ankit

Your affiliation

IITM

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

Dear Geos-Chem Community
I am running a GEOS-Chem simulation over the nested Indian region and observing extremely low fine chloride concentrations compared to measurements. I am using GT-Chlorine emissions, which provide anthropogenic HCl emissions. Interestingly, the model output over a Chinese city aligns well with observations without any scaling, but over India, the predicted fine chloride levels are significantly lower than observed values. Initially, I suspected that the emissions over India might be underestimated, so I applied different scale factors. At around a 10x scale factor, the model output becomes somewhat comparable to observations. However, increasing emissions by 10 times seems highly unrealistic, which raises concerns about potential issues elsewhere in the model setup. I am trying to understand whether I am making an error in my approach, whether the applied scale factors are reasonable, or if there could be another factor affecting the fine chloride concentrations in my simulation.
Has anyone encountered a similar issue or has insights into what might be causing this discrepancy?
Any guidance would be greatly appreciated.

following is the model vs observation in my simulation
https://drive.google.com/file/d/1YkUf6RgWt5uEZwj70gN3USDwKWWGg7K_/view?usp=drive_link

Following is a study where same emission inventory is used for comparison over China (https://pubs.acs.org/doi/10.1021/acs.est.4c05037)
https://drive.google.com/file/d/1U82VYD6Gj-OgYkO0eDogQH_sLXYTlgDA/view?usp=drive_link

HEMCO_Config file
https://drive.google.com/file/d/1QVpVM7HbPjrUt-f6vgwQZNakWVYUcCJS/view?usp=drive_link

Thanks in advance

[yantosca]

Thanks for writing @ankitpatel0698. This is more of a science question and as such would be better posed to the Aerosols WG. Tagging @beckyalexander @theloniuspunk @wporter

[yantosca]

You can also email the Aerosols WG email list: geos-chem-aerosols [at] g.harvard.edu