Global Reanalysis Intercomparison of Potential Vorticity

Abstract:

Global reanalyses from data assimilation systems are among the most used datasets in the study of weather and climate because they provide globally gridded high-resolution meteorological fields based on general circulation models constrained by observational data. In this study, we assess how consistently reanalyses represent potential vorticity (PV) among each other. In particular we assess the National Centers for Environmental Prediction Climate Forecast System Reanalysis/Climate Forecast System, version 2 (CFSR/CFSv2) reanalysis, the European Centre for Medium-Range Weather Forecasts Interim (ERA-Interim) reanalysis, the Japanese Meteorological Agency’s 55-year (JRA-55) reanalysis, and the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2).

PV helps describe dynamical processes in the stratosphere because it acts approximately as a tracer of the movement of air parcels; it is extensively used to identify the location of the tropopause and to identify and characterize the stratospheric polar vortex. In this study, we assess the representation of PV in all of these facets.

©2020 California Institute of Technology. U.S. Government sponsorship acknowledged.