Ongoing research project |
2014 - 2017

ERA-CLIM2 is an international research project in the area of climate reanalysis, coordinated by ECMWF.

                 maps showing wind and mslp observations at 1900, 1950 and 2010 and the corresponding climate reanalysis fields of mslp and 2m temperature

Atmospheric and ocean observations rescued and stored in international data sets are assimilated by the ECMWF coupled assimilation system to produce a coupled global reanalysis over the 20th century (CERA-20C)

The core objective of ERA-CLIM2 project is to apply and extend the current global reanalysis capability in Europe, in order to meet the challenging requirements for climate monitoring, climate research, and the development of climate services. The project focus is on production and assessment of multi-decadal reanalyses of the global climate system including atmosphere, land, ocean, and cryosphere, combined with consistent information on the carbon cycle. Two types of reanalysis will be produced: an extended climate reanalysis of the 20th century at moderate resolution, and a higher-resolution reanalysis of the satellite era for near-real time climate monitoring. The project includes a coherent research and development program in coupled data assimilation, specifically targeted to extend current capability to future fully-coupled climate reanalyses. In addition, substantial work will be directed at data recovery, reprocessing, and quality control of input observations for reanalysis, with emphasis on improving and extending the usable satellite climate data records, and expanding access to early 20th century in-situ observations. The challenging problem of providing meaningful uncertainty information for users of reanalysis data will be addressed by using ensemble techniques in reanalysis production, by conducting a variety of detailed quality assessments of input observations as well as reanalysis output, and by providing open and complete access to data and data visualization tools for users. 


First General Assembly, ECMWF, 19-21 November 2014

Second General Assembly, EUMETSAT, 9-11 December 2015

ERA-CLIM2 M27 Review/Progress Meeting, 25-26 April 2016

ERA-CLIM2 User workshop on observations for reanalyses – Organized as one of the sessions of the 9th ACRE (Atmospheric Circulation Reconstructions over the Earth) Workshop and Historical Weather and Climate Data Forum, University of Maynooth, Ireland – 20-24 June 2016. A short report of the ERA-CLIM2 contribution is available here.

Workshop on Coupled Data Assimilation, planned to be co-organized with Météo-France and the WMO, Toulouse – 18-21 October 2016 (

WP2 Progress Meeting – Planned to be organized in conjunction with the ‘International workshop on coupled data assimilation’ at Météo France, Toulouse – 18-21 October 2016

ERA-CLIM2 3rd General Assembly – University of Vienna (organized by L Haimberger) - 16-18 January 2017

ERA-CLIM2 36M Review Meeting - University of Vienna - 19 January 2017


More information

ERA-CLIM2 Project website

This project has received funding from the European Union’s Framework Programme under grant agreement number 607029.