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The GEMS production systems and retrospective reanalysis Adrian Simmons. GEMS production systems and reanalysis will build on several ECMWF activities, including:. ERA-40 ENVISAT cal/val and assimilation experience Development of analysis of CO 2 from AIRS radiances
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The GEMS production systems and retrospective reanalysis Adrian Simmons
GEMS production systems and reanalysis will build on several ECMWF activities, including: • ERA-40 • ENVISAT cal/val and assimilation experience • Development of analysis of CO2 from AIRS radiances • Development of fast RT models • Other developments of the ECMWF forecasting system
The ERA-40 data assimilation system • A reanalysis from September 1957 to August 2002 • Based on cycle 23r4 of ECMWF forecasting system - operational from June 2001 to January 2002 • Six-hourly 3D-Var analysis - operations uses 12-hourly 4D-Var • T159 horizontal resolution (~125km grid) - operations uses T511 (~39km grid) • Uses full 60-level resolution
CRUTEM2v from Jones and Moberg (2003) ERA-40 Trend and variability in two-metre temperature over land CRUTEM2v from Jones and Moberg (2003) Linear trend: CRUTEM2v 0.171OC/decade ERA-40 0.169OC/decade
Linear trend in two-metre temperature (OC/decade) ERA-40 CRUTEM2v from Jones and Moberg (2003)
MSU-4 data analyzed by Mears et al. (2003) ERA-40 equivalent from Ben Santer, PCMDI Trend and variability in lower stratospheric temperature Linear trend: MSU-4 - 0.39OC/decade ERA-40 - 0.30OC/decade NCEP - 0.82OC/decade
Blue: ERA-40 (TOMS and SBUV data assimilated 1979-1988 and 1991-2002) Red: Ground-based measurements (NOAA/CMDL) Total ozone (following Pascal Simon, Météo-France)
1 1 ERA-40 Model simulation 10 10 hPa hPa 100 100 One year One year Equatorial specific humidity
ERA-40 SSM/I retrievals from Remote Sensing Systems 24h forecast 24 - 36h forecast Year Humidity and rainfall over the tropical oceans
Remote use of data assimilation system • ERA-40 production system was based on ECMWF’s prepIFS software for preparing and managing experimentation with its forecasting system • prepIFS is available to Member-State users of the ECMWF forecasting system • ERA-40 system was used remotely by Reading University and KNMI for studies of data denial • Updated system will be available to GEMS partners • GEMS funding will enable ECMWF to provide better support for external users than possible for ERA-40
Reanalysis plans beyond ERA-40 • An interim reanalysis • Start next year, T159L60 (L91?), latest version of forecasting system • Run from 1991 (tbd) onwards, continued in close to real time • Basis for future developments (including GEMS) • Experimentation • To validate new versions of forecasting system • High-resolution 4D-Var analyses for specific cases • Observing system experiments • Development of observational data base and processing software • An extensive new reanalysis in 2008 or beyond
Total ozone 1 October 2003 No MIPAS With MIPAS TOMS
Sonde With MIPAS No MIPAS 26 Aug 2003 11 Sept 2003 22 Sept 2003 Ozone profiles at Neumayer (71S, 8W)
Ozone in the tropics 1 August 2003 ECMWF TOMS No MIPAS With MIPAS
CO2 assimilation from AIRS - Troposphere Monthly mean distribution for May 2003 is shown on the left, and the upper boundary for the error estimate is shown on the right.
Fast RT code development • Standard RTTOV software has been adapted to include variable CO2 • RTIASI has been extended to include variable CO2, CH4, N2O and CO; work on aerosols is planned • RTTOV is being developed to handle limb-sounded radiances from MIPAS (as part of development for a capability for direct assimilation of these radiances)
Forecasting-system development • 91-level model with improved resolution of tropopause and stratopause/mesosphere, plus work on gravity-wave parametrization and treatment of biases in data assimilation – to address stratospheric problems • Work on humidity analysis, assimilation of rain-affected microwave radiances – to reduce spin-down • Model has been extended to handle extra fields • Work to extend Jb is planned for 2004 • Work on parametrization of convection and vertical diffusion to enable tracer transfer is planned for 2004