NCEP–DOE AMIP-II Reanalysis (R-2)

Abstract

The NCEP?DOE Atmospheric Model Intercomparison Project (AMIP-II) reanalysis is a follow-on project to the ?50-year? (1948-present) NCEP-NCAR Reanalysis Project. NCEP?DOE AMIP-II reanalysis covers the ?20-year? satellite period of 1979 to the present and uses an updated forecast model, updated data assimilation system, improved diagnostic outputs, and fixes for the known processing problems of the NCEP-NCAR reanalysis. Only minor differences are found in the primary analysis variables such as free atmospheric geopotential height and winds in the Northern Hemisphere extratropics, while significant improvements upon NCEP-NCAR reanalysis are made in land surface parameters and land-ocean fluxes. This analysis can be used as a supplement to the NCEP-NCAR reanalysis especially where the original analysis has problems. The differences between the two analyses also provide a measure of uncertainty in current analyses.