How are human activities impacting the composition of the atmosphere on local, regional and global scales?

Answering this question is critical for predicting future changes in pollution and climate and depends centrally on our knowledge of the underlying chemistry. Implicitly, it also requires us to know what the natural chemical state of the atmosphere is in the absence of perturbations by human activities.

Photo-induced free radical gas-phase oxidation, gas-surface and gas-droplet interactions, particle nucleation and growth, among a myriad of other processes, participate in controlling the fate of human-induced emissions and thus atmospheric composition. This chemistry, coupled with atmospheric transport phenomena, makes answering the initial question a challenging, yet interesting, research endeavor.

Current research efforts in our group are aimed at developing a detailed understanding of such processes from the molecular to the regional and global scales via a combination of fundamental laboratory studies and in situ atmospheric observations.