An Evaluation of the Apparent Interdecadal Shift in the Tropical Divergent Circulation in the NCEP–NCAR Reanalysis

Abstract

Recent decadal regime shifts in the large-scale circulation of the tropical atmosphere are examined using analyses and independent observations of the circulation and precipitation. Comparisons between reanalysis products and independent observations suggest that the shifts that are apparent and significant in the reanalysis products may be artifacts of changes in the observing system and/or the data assimilation procedures.