Hi everyone,
I have used DDM to calculate the sensitivity of NO₂ pollutant concentrations to NOx emissions and I noticed that the output units are “ppmV”. Could you confirm if this is reasonable for DDM sensitivity outputs?
Additionally, assuming I have an observed NO₂ value from observation data and a modeled NO₂ value from CMAQ, I calculated the difference between them. I attempted to estimate the emission adjustment using the formula:
However, I found that the resulting emission adjustment is very small, showing almost no significant change. Interestingly, when I multiplied the result by the original emission inventory value, the adjusted emission difference became more reasonable. Could this issue be related to the units of the DDM sensitivity output? I would greatly appreciate your insights on whether this approach is correct and if the units of the sensitivity output might be affecting the calculation.
Thank you for your time and assistance. I look forward to your guidance.
Best regards,
Jimmy