ERA-40 Atlas

Each re-analysis creates a new view of the climate of the earth and its variations. This is based on information provided by the data-assimilation system (model and analysis) and on external information from observations and boundary conditions. Time consistency is a very important consideration for climate studies and, since, in the context of re-analysis, the data-assimilation is applied with minimum changes through the period, the re-analysis products are more suitable for climate research than the routinely produced operational analyses.

ERA    The University of Reading    ECMWF    WCRP