What controls Atmospheric Composition?
The mixture of trace gases and particles in the atmosphere is controlled by the emission, photochemistry and transport of many trace species. Understanding the time scale as well as the chemical and spatial patterns of perturbations to these species is needed to evaluate possible environmental damage (e.g. stratospheric ozone depletion or climate change) caused by anthropogenic emissions of chemically reactive species. Treating global atmospheric chemistry as a linearized system and analyzing it in terms of eigenvalues gives insight into chemical patterns or modes as well as the time scales of response of the system. This talk focuses on those chemical feedbacks that couple perturbations across all species. First results are presented for 3-D modeling of stratospheric chemistry linking both methane and nitrous oxide and for characterization of the one of the longest, important chemical modes in the atmosphere – that coupling N2O, NOy, CH4, and O3.
