1. Summary 26 September 2012 Core Theme 4: Predictability of the THC Lead: W. Hazeleger (KNMI) Participants: ECMWF, UREAD, GEOMAR, MET-O, MPG, KNMI

2. Deliverable report D28. Impact of observing system on the predcitability of the MOC : UKMO (Nick Dunstone) 1990: 2008: Temperature Salinity

3. Deliverable report D 41: Implication of idealized observing system experiments for needs of observing system. Lessons learned from optimal perturbations of ocean circulation UKMO (Nick Dunstone with input Ed Hawkins) MPI-M results need to be checked.

4. Deliverable report D39: Relative impact of initial condition and forcing. Quantifying this impact. ECMWF (Susanna Corti)

5. Deliverable report D40: Assessment of THC predictions up to 2030 predictions GEOMAR (Mojib Latif) See presentation on uncertainties of future predictions by T. Martin and input from MPI, UKMO on 30-yr initialized predictions

6. Work package 3rd period (last year) WP 4.1 Wilco Hazeleger Bible: Results on additional analysis of decadal hindcasts and predictions, relative impact initial state/forcing, singular vector perturbations Apocrif books: Statistical model predictions (UREAD), Reliability and probablistic skill of initialized and uninitialized predictions (ECMWF), skill from wind initialization only (GEOMAR) WP 4.2 Doug Smith Bible: description of results of observing system experiments Results (from deliverable reports), publications, efforts and use of resources (pms), ….. P

7. Final report Deadline 10 Dec. All our publications 6 pager, executive summary style - Multi model predictions (2 pages Wilco) - Prediction strategies (1 page Ed) - Impact initalization/forcing + BSS noinit/init (1 page Susanna) - Observing system (2 pages Doug) 1 page future directions (Wilco)

8. Future directions Model bias remains a major issue. Clearly higher resolution in ocean and atmosphere needed Further studies prediction strategies needed (initialization, perturbation). THOR worked with rather ad-hoc strategies. More in depth analysis of the hindcasts and predictions needed Dominant role of initial conditions has been quantified for essential ocean and climate variables and show need for good ocean analyses Full depth ARGO should be extended, ocean transports and flux measurements are needed for verification Probabilistic verification needed (if data allows so). Reliability may be more important than skill.

9. THOR is a project financed by the European Commission through the 7th Framework Programme for Research, Theme 6 Environment, Grant agreement 212643 http://ec.europa.eu/index_en.htmhttp://ec.europa.eu/index_en.htm