1. Climate reanalysis at ECMWF Reanalysis is based on analysis methods developed to provide initial states for numerical weather prediction It applies a fixed, modern data assimilation system to multi-year sets of observations of different types New reanalysis products benefit from improvements in forecast skill, data assimilation methods, and ongoing data recovery and data reprocessing efforts ECMWF operational forecasts % “Forecasts” from ECMWF reanalyses %

2. ERA-CLIM Project Overview bilat 2011

3. The ERA-CLIM Project ERA-CLIM: European Reanalysis of Global Climate Observations 3-year collaborative research project, start date 01/01/2011 Funded by EU research FP7, Environment theme Total cost €4.9M; EC contribution €3.5M 8(9) partners, 47.5(59) person-years, 50 deliverables bilat 2011

4. Objectives Addressing the call for proposals: Building observational datasets for the predictability of global atmospheric, oceanic and terrestrial processes using reanalysis techniques As stated in the project proposal: Development of the observational record for the early 20 th century Preparation of satellite observations, boundary conditions, and forcing data for an atmospheric reanalysis of the 20 th century (ERA-20C) Development of an Observation Feedback Archive for reanalysis Production of pilot case reanalyses and data quality information Assessment and reduction of data uncertainties Additional goals: Improving access to climate data, quality, and transparency Developing a sustained data recovery and reanalysis capability Meeting the requirements for future GMES climate services bilat 2011

5. Deliverables ObjectivesKey deliverables Development of the observational record for the early 20 th century Inventories; database for metadata, web-based digitising tools WP1 Digitized, quality-controlled instrumental records for the early 20 th century Access to observations and metadata via international data centres Preparation of reprocessed satellite observations, boundary conditions, and forcing data Reprocessed satellite data sets for input to reanalysis; early satellite records WP2 Ensemble of consistent sea-surface boundary conditions for the 20 th -century Atmospheric forcing data (solar, aerosols, GHG, land surface…) for ERA-20C Development of an Observation Feedback Archive (OFA) Database facility for input observations with quality feedback from reanalyses WP3 A series of long test reanalyses at various resolutions to prepare for ERA-20C Production of pilot reanalyses and data quality information All reanalysis products and input observations available via web services Assessment and reduction of data uncertainties Homogenized in-situ data and bias correction techniques WP4 Improved ocean observations for reanalysis Tools for quality assessment of reanalysis products bilat 2011

6. Work packages 1.Recovery, imaging, and digitisation of historical observations and metadata 2.Preparation of satellite observations, boundary conditions, and forcing data 3.Integration of observational climate data sets (reanalyses) 4.Quantifying and reducing uncertainties 5.Project management and coordination bilat 2011

7. WP1: Recovery, imaging, and digitisation of historical observations and metadata Deliverables (9): Person-months (268): bilat 2011 WP1 lead is UBERN Involves 47% of project resources Strong leverage on ACRE (via UKMET) Addition of DMC is crucial for this WP

8. WP2: Preparation of satellite observations, boundary conditions, and forcing data Deliverables (13): Person-months (66): bilat 2011 WP2 lead is UKMET Deliverables are largely independent Direct input to WP3

9. WP3: Integration of observational climate datasets (reanalyses) Deliverables (10): Person-months (80): bilat 2011 WP3 lead is ECMWF Will generate 1Pb of reanalysis data OFA is a new development

10. ERA-CLIM pilot reanalyses WhatPeriodResolutionEnsWhenVol ERA-IntInterim reanalysis1989-NRTT255L601ongoing33 Tb ERA-P0 AMIP ensemble1900-2011T159L9110Jun 2011 (9M) ERA-P1 EDA using sfc obs only1900-2011T159L9110Sep 2011 (15M)655 Tb ERA-S1 Land surface using ERA-P11900-2011T7991Sep 2012 (9M)77 Tb ERA-P2 Reanalysis using all obs2 early decadesT511L911Sep 2012 (9M)180 Tb ERA-E2 As ERA-P2 but with SST/sea-ice perturbations 2 early decadesT159L9110Jan 2013 (9M)180 Tb ERA-P3 To replace ERA-Interim1979-NRTT511L911Jan 2012 (24M+)234 Tb ERA-20C20 th -century reanalysis1900-NRTT511L911 2014 (36M+)1062 Tb ERA-CLIM ECMWF Contributions

11. WP4: Quantifying and reducing uncertainties Deliverables (9): Person-months (135): bilat 2011 WP4 lead is UNIVIE Complex set of deliverables OFA is a crucial resource for this WP

12. WP5: Project management and coordination Deliverables (9): Person-months (18): bilat 2011 WP5 lead is ECMWF 2 person-months for each WP lead

13. bilat 2011 Meantime…

14. Conclusions ERA-CLIM is an essential step towards the future ECMWF global reanalysis ERA-20C. This project is directly supported by EU-FP7 Additional support to reanalysis activities is provided by: – ESA – Japan – UK (NCEO, NCAS) ERA-interim remains the best reanalysis in the world in many aspects – This resource should be used widely by the climate community bilat 2011