Comparison of the stratospheric polar vortices in five reanalyses datasets

The SPARC Reanalysis Intercomparison Project (S-RIP) is an international program aimed at providing guidance to users of reanalysis datasets on model and data assimilation details, strengths, weaknesses, and biases of individual reanalysis datasets and advisories on which reanalysis datasets are optimum to study different atmospheric phenomena. As part of that effort, this work reports on differences in the representation of the stratospheric and mesospheric polar vortices in five different reanalysis datasets. We will show an in-depth evaluation of polar vortex size, shape, strength, and longevity in both the Arctic and Antarctic polar vortices in MERRA, MERRA-2, ERA-Interim, JRA-55, and CFSR. Comparison of vortex properties will be performed both during quiet times and during highly disturbed sudden stratospheric warming events. Differences in the polar vortices among the reanalyses will be interpreted alongside differences in the polar night jet and planetary wave behavior embedded in the background flow. Comparison to independent satellite observations will ultimately yield recommendations for which reanalyses sets most accurately capture observed structure and variability.