Solution
Using the formaldehyde to nitrogen dioxide ratio from satellite data can provide some insight as to whether a region is NOx sensitive or VOC sensitive for ozone formation. I have linked a publication below by Jin, X et al., 2018 that provides more insight to this topic. Additionally, there is a user friendly tutorial on the Holloway Group website on how to plot this ratio using satellite data (also linked below).
Publication: https://academiccommons.columbia.edu/doi/10.7916/D8M34C7V
Tutorial: https://hollowaygroup.org/tutorials
