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Recently, you may have heard about a new internet security weakness, known as Heartbleed, which is impacting some websites. There is no indication that Heartbleed has been used against or that any personal information has ever been at risk. However, we are asking users to change their current password out of an abundance of caution to ensure the protection of your information. logoReanalysis is a scientific method for developing a comprehensive record of how weather and climate are changing over time. In it, observations and a numerical model that simulates one or more aspects of the Earth system are combined objectively to generate a synthesized estimate of the state of the system. A reanalysis typically extends over several decades or longer, and covers the entire globe from the Earth’s surface to well above the stratosphere. Reanalysis products are used extensively in climate research and services, including for monitoring and comparing current climate conditions with those of the past, identifying the causes of climate variations and change, and preparing climate predictions. Information derived from reanalyses is also being used increasingly in commercial and business applications in sectors such as energy, agriculture, water resources, and insurance.


Using a collaborative Wiki framework, the goal of is to facilitate comparison between reanalysis and observational datasets. Evaluative content provided by reanalysis developers, observationalists, and users; and links to detailed data descriptions, data access methods, analysis and plotting tools, and dataset references are available. Discussions of the recovery of observations to improve reanalyses is also a focus. The wiki framework encourages scientific discussion between members of and other reanalysis users. 


Differences between CGCM, Reanalysis and Observational multidecadal variability Discussion Page

Reanalyses Intercomparison Tool  (WRIT) BAMS article:
  Link to WRIT tools

Ana4MIPS: Providing access to netCDF formatted reanalysis data of selected variables, repackaged corresponding to the CMIP5 climate model output and Obs4MIPS standards at the Earth System Grid Federation (includes CFSR, MERRA, 20CR, JRA-25, ERA-Interim).

JRA-55: The new Japanese 55-year Reanalysis (1958 to present) is available from multiple data providers.

ERA-20C: ECMWF just released their first reanalysis of the 20th century. More details here.