ENSEMBLE at ECMWF

What is ENSEMBLE? The European-funded ENSEMBLES project defined two experimental protocols. The first (stream 1), is essentially a set of test integrations, covering the 11 years 1991-2001 and with May and November start dates only. The second, stream 2, is essentially equivalent to the CHFP protocol.
ENSEMBLE project outputs data currently hosted on http://ensemble.cima.fcen.uba.ar:9090/thredds/catalog.html



The seasonal-to-decadal (s2d) experiments comprise two sets of simulations: the so-called Stream 1 and Stream 2 simulations. For both streams, coordinated forecast experiments over seasonal, interannual and decadal timescales have been performed. Three different approaches are being pursued to represent model uncertainties: the multi-model approach, the perturbed physical parameter approach and the stochastic physics approach.

Description of the s2d experiments
Stream 1:

    Seasonal and annual ensemble integrations
  • 2 start dates per year: 1st of May and November
  • 7 month hindcasts for May and 14 for November
  • Hindcast production 1991-2001
  • 9-member ensembles
    Multi-annual ensemble integrations
  • Two hindcasts started on the first of November 1965 and 1994
Stream 2:
    Seasonal and annual ensemble integrations
  • 4 start dates per year: 1st of February, May, August and November
  • 7 month hindcasts for every start date, except 14 for those starting in November
  • Hindcast production 1960-2005, using ERA-40 up to August 2002 inclusive and ECMWF operational analyses afterwards
  • 9-member ensembles
    Multi-annual ensemble integrations(minimum set)
  • One hindcast every 5 years
  • 10 year runs starting on 1st of November 1960, with the next one starting in November 1965 and so on
  • Hindcast production 1960-2005
  • 3-member ensembles

Further information about ENSEMBLE Experimental Set Up available: here