ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Overview of Seasonal-to-Decadal (s2d) Activities during the Initial

18 Months

Francisco J. Doblas Reyes

European Centre for Medium-Range Weather Forecasts

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

RT1 activitiesRT1: Development of the EPS

• Aim: assess best method to estimate model uncertainty.

• Estimates of model uncertainty using a new multi-model ensemble, a recently developed stochastic physics scheme (ECMWF and Met Office) and the perturbed parameters approach (Met Office with 2 different versions of HadCM3).

• Ocean initial conditions from ENACT and generation of new sets when possible.

• Common output archived in MARS (atm) and ECFS (ocean).

• Pre-production for 1991-2001 with reduced start dates and completion for end 2005.

• Additional experiments to test the consistency of the predictions and the impact of the ensemble size.

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Generalized ensemble approach

Uncertainty

initial conditionsmodel formulation

Estimation

ensemblemulti-model

multi-model ensemble forecast multi-model ensemble forecast systemsystem

N models x M ensemble membersN models x M ensemble members

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Generalized ensemble approach

Uncertainty

initial conditionsmodel formulation

Estimation

ensemble perturbed parameters

perturbed parameters ensembleperturbed parameters ensemble

N versions x M ensemble membersN versions x M ensemble members

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Generalized ensemble approach

Uncertainty

initial conditionsmodel formulation

Estimation

ensemble with stochastic physics

Ensemble with stochastic physicsEnsemble with stochastic physics

M ensemble membersM ensemble members

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Multi-model ensemble system

Partner Atmosphere Ocean

ECMWF IFS HOPE

ECMWF IFS OPA

CNRM ARPEGE OPA

CERFACS ARPEGE OPA

UKMO GloSea

UKMO HadCM3

MPI ECHAM5 MPI-OM1

• Hindcast production period for: 1991-2001

9-member ensembles

ERA-40 atmosphere and soil initial conditions

ENACT-based ocean initial conditions with SST and wind perturbations

2 seasonal,1 annual runs per year

At least 2 multi-annual runs (1965 and 1994)

Boundary forcings in forecast mode: GHGs, aerosols, solar forcing, etc.

• ENSEMBLES system: 7 coupled GCMs running at ECMWF

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Multi-model ensemble system

Feb 87 May 87 Aug 87 Nov 87 Feb 88 ...

6 models x 9 ensemble members

54 member multi-model ensemble

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Multi-model ensemble system

Feb 87 May 87 Aug 87 Nov 87 Feb 88 ...

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Multi-model ensemble system

Feb 87 May 87 Aug 87 Nov 87 Feb 88 ...

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Multi-model ensemble system

Feb 87 May 87 Aug 87 Nov 87 Feb 88 ...

54 member multi-model ensemble

= 1 hindcast

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

RT2A activitiesRT2A: Global model engine

• Build on the RT1 experience.

• Starting in ~month 24: seasonal, annual and multi-annual integrations.

• New set of (ensemble) ocean initial conditions from ENACT and/or RT1.

• Common output (based on RT1 lists and scripts) archived in MARS and ECFS.

• Dissemination based on public data and OPenDAP servers.

• Production period 1960-2001.

• 4 times per year, multi-annual hindcasts with the perturbed-parameter approach (HadCM3 or HadGEM).

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Multi-model ensemble system

Partner Atmosphere Ocean

ECMWF IFS OPA

CNRM ARPEGE OPA

UKMO GloSea

MPI ECHAM5 MPI-OM1

INGV ECHAM4 OPA

• ENSEMBLES system: 5 coupled GCMs (4 running at ECMWF)

• Hindcast production period for: 1960-2001

9-member ensembles

ERA-40 atmosphere and soil initial conditions

RT1-based ocean initial conditions

4 seasonal, 1 annual runs per year

At least 1 multi-annual run every 5 years

Boundary forcings in forecast mode: GHGs, aerosols, solar forcing, etc.

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Data storage• Archiving at ECMWF (seasonal to decadal) and M&D

(decadal to centennial in CERA).

• Use of a common list of variables (minimum requirement) for atmosphere and ocean variables.

• Atmosphere (GRIB) in MARS and ocean (NetCDF) in ECFS. Need of an ENSEMBLES class for MARS.

• Scripts available for archiving and retrieval.

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Data storage

http://cera-www.dkrz.de/CERA/

Global change

integrations in CERA

and PCMDI

Seasonal to decadal in MARS and ECFS

http://www.ecmwf.int/services/archive/

ENSEMBLES RT4/RT5 Joint Meeting Paris, 10-11 February 2005

Questions?