Is our dynamical understanding of the circulation changes associated with the Antarctic ozone hole sensitive to the choice of reanalysis dataset?

Abstract. This study quantifies differences among four widely used atmospheric reanalysis datasets (ERA5, JRA-55, MERRA-2, and CFSR) in their representation of the dynamical changes induced by springtime polar stratospheric ozone depletion Southern Hemisphere from 1980 to 2001. The intercomparison is undertaken as part SPARC (Stratosphere–troposphere Processes Role Climate) Reanalysis Intercomparison Project (S-RIP). reanalyses are generally good agreement strengthening lower vortex during austral spring–summer season, associated with reduced radiative heating due loss, well descent anomalously strong westerly winds into troposphere summer subsequent poleward displacement intensification front jet. Differences trends zonal wind between small compared mean trends. exception CFSR, which exhibits greater disagreement other three datasets, stronger stratosphere spring a larger tropospheric jet summer. hole examined investigating momentum budget then eddy heat fluxes terms planetary- synoptic-scale Rossby wave contributions. consistently represented across support our understanding response coupled stratosphere–troposphere system hole. Although results suggest high degree consistency these changes, there forcing, residual circulation, propagation In particular, noticeable disparity CFSR reanalyses, while best found ERA5 JRA-55. Greater uncertainty components budget, opposed suggests that better constrained assimilation observations fluxes, more dependent on model-based forecasts can differ reanalyses. Looking forward, however, findings give us confidence be assess ongoing recovery ozone.