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 %

ERA-CLIM Project Overview bilat 2011

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

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

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

ERA-CLIM pilot reanalyses WhatPeriodResolutionEnsWhenVol ERA-IntInterim reanalysis1989-NRTT255L601ongoing33 Tb ERA-P0 AMIP ensemble T159L9110Jun 2011 (9M) ERA-P1 EDA using sfc obs only T159L9110Sep 2011 (15M)655 Tb ERA-S1 Land surface using ERA-P T7991Sep 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-NRTT511L (36M+)1062 Tb ERA-CLIM ECMWF Contributions

bilat 2011 Meantime…

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

ESA bi-lateral, 2011 ESA CCI – CMUG/ECMWF CMUG consortium Met Office (Prime contractor) Roger Saunders plus others Meteo France, MPI-M ECMWF Role is advisory - giving feedback to ESA and ECV teams Key test for uptake of ECV products by climate modelling/reanalysis community All CMUG members are potential users of ECV products Additionally ECMWF provides data as ancillary input We have a strategic interest in climate-quality datasets Equipped to advise on what constitutes climate-quality Especially from an integrated perspective