Reanalysis

Comprehensive weather and climate datasets, reanalyses assimilate a variety of observations of the atmosphere, land surface, and ocean into a forecast model to provide a dynamically consistent estimate of the climate state at each time step.

Below is the atmospheric reanalysis overview page, which summarizes the attributes of the major atmospheric reanalyses. This section also includes selected oceanic reanalyses, although an overview is not available yet.

To find a specific reanalysis, jump to the search box below or click your desired reanalysis from among the blue sub-category buttons.

To see only the reanalyses pages accompanied by in-depth commentary, select the "Datasets with guidance" button when using the search box.

Climate datasets

Has expert guidance
ERA5 atmospheric reanalysis ERA5 atmospheric reanalysis
  • Years of record

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ERA5, the successor to ERA-Interim, provides global, hourly estimates of atmospheric, ocean-wave and land-surface variables, at a horizontal resolution of 31 km and 137 levels in the vertical from the surface to 0.01 hPa (about 80km). Produced by ECMWF on behalf of the…

Main variables and Earth System components

Atmosphere Land Ocean wave height
ERA-Interim ERA-Interim
  • Years of record

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Using a much improved atmospheric model and assimilation system from those used in ERA-40, ERA-Interim represents a third generation reanalysis. Several of the inaccuracies exhibited by ERA-40 such as too-strong precipitation over oceans from the early 1990's onwards and a…