New paper out from the CMAQ adjoint team, now in final form at Geoscientific Model Development. Link is: https://gmd.copernicus.org/articles/13/2925/2020/gmd-13-2925-2020.html
Sensitivity of sulfate to SO2 via the adjoint model (left). Cloud-mediated oxidation.
The Iowa group's contribution was through early development on the aqueous chemistry adjoint (see Fahey et al. 2017 https://www.geosci-model-dev.net/10/1587/2017/gmd-10-1587-2017.html )