Satellite records of total ozone indicate a systematic decline at midlatitudes after 1980. A clue to the origin of these changes comes from their strong seasonal and geographical dependence which mirror the seasonality and structure of total ozone itself. Numerical models underestimate the observed trend in midlatitude total ozone, with models predicting only half of the observed decrease. Dr. Salby and his colleagues believe the discrepancy may stem from sources of interannual variability not currently accounted for in model simulations.
Accordingly, Dr. Salby and colleagues will explore interannual variations of ozone in relation to variations of tropospheric structure. Following preliminary results from a pilot study, they will composite interannual variations of stratospheric chemical and dynamical structure. Interannual variations of tropospheric structure composited in a similar fashion will then be used to drive numerical integrations in an investigation of how stratospheric changes depend on changes in planetary wave activity and other tropospheric features influencing ozone.
