Characterizing and explaining mesospheric ozone

Susan Solomon’s contributions to understanding ozone in the middle atmosphere include investigations specifically focused on the ozone distribution and chemical reactions in the mesosphere and the key role that ozone plays in the energetics driven by UV absorption and other solar input. The book she co-authored with Guy Brasseur (Aeronomy of the Middle Atmosphere, 2005) remains the go-to source of information about the reactions and other processes affecting mesospheric ozone and atomic oxygen. The basic description of the important chemical processes has not changed. Nevertheless, despite ongoing research and global observations, there are still unanswered questions about mesospheric ozone. There is not yet a convergence on even the basic question of just how much ozone there is. Additional uncertainty comes from the effect that molecular and eddy diffusion have directly or indirectly on oxygen species. This presentation will review current questions and describe why they have not been resolved even after several decades of satellite observations and comprehensive whole atmosphere modeling.