I’m recently using CMAQ-ISAM to simulate regional transport and I noticed that when my simulated domain is smaller, the percentage of BCON in each city is bigger, on the contrary, when my simulated domain is enlarged, the percentage of BCON in the same city decreases.
I would like to know if the BCON results are related to the size of the simulation domain?
Also, I found that cities located in the center of the simulation domain are less affected by BCON than cities near the boundary of the simulation domain. Is the effect of BCON on cities within the same simulation domain related to the distance of the city from the boundary?
Thank you for your answer!
Since the BCON tag reflects the contribution of inflow from the boundaries to simulated concentrations, what you are describing is the expected behavior - the smaller the domain, and the closer a grid cell is located to the (inflow) boundaries, the larger the expected BCON contribution.