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
ERA-Interim ERA-Interim
  • Years of record

  • to

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…

ERA40 ERA40
  • Years of record

  • to

ERA 40 is a second generation reanalysis. It is the first reanalysis to directly assimilate satellite radiance data (TOVS, SSM/I, ERS and ATOVS). Cloud Motion Winds are also used. The result is better circulation over the tropics and southern hemisphere.…

Main variables and Earth System components

Atmosphere Air Temperature Geopotential Height Water Vapor
  • Experts contributing reviews

  • None
Climate Data Guide ERA-15
  • Years of record

  • to

The ERA-15 production system generated re-analyses for 15 years (1979-1993)  using a special version of their 1995 operational data assimilation system and model. The resulting analyses include full model resolution analyses or  reduced resolution analyses and…

Main variables and Earth System components

Atmosphere