IGST 12 – August 2007 – St Johns GODAE-OOPC OSSE/OSE meeting Paris, November The GODAE initial requirements and a strategy for a global observing system have been described in the OceanObs99 conference book. By the end of GODAE, more specific requirements should be made on the basis of improved understanding of data utility and a series of recommendations for an improved design of the global ocean observing system should be delivered. Global ocean state estimation systems are a powerful means to assess the impact of the observing system, to identify gaps and to improve the efficiency/effectiveness of the observing system. OSEs (Observing System Evaluations) or OSSEs (Observing System Simulation Experiments) are, in particular, useful tools. Impact on applications is another issue and should also guide OSEs/OSSEs studies (e.g.optimizing surface current forecasts for marine safety applications). => hold a GODAE/OOPC workshop on OSEs/OSSEs in fall 2007 to improve the collaboration and sharing of OSSEs and OSEs results between GODAE, OOPC, CLIVAR and other groups. (PYLT, EH, AF)

IGST 12 – August 2007 – St Johns Workshop objectives Review work done on OSEs and OSSEs over the past years Identify robust and common features Provide good examples of the contribution of observing system Provide preliminary recommendations on the observing system design. What needs to be improved ? Specific topics should include: Low/high resolution altimetry Argo Tropical moorings High resolution SSTs New observing techniques (e.g. salinity, gliders) Scatterometry Prior to the workshop, specific impact studies should be defined and carried out by the different groups so that results can be compared and discussed at the workshop. Outcomes of the workshop : a first list of recommendations for the global observing system, a work plan to prepare the GODAE recommendations and (mainly) to make a better case to for the global ocean observing system (final GODAE conference)

IGST 12 – August 2007 – St Johns Feedback from OOPC meeting. The workshop will be focused on the impact in GODAE systems (mainly high resolution). Will not/cannot cover all aspects (in particular for climate issues). Should help to prepare a contribution to the St Raphael follow on conference (2009) Participants (invitation only). 24 people confirmed (2 to 3 more expected). 5-7 November 2007, UNESCO/IOC (Salle XV), Paris, France

IGST 12 – August 2007 – St Johns Issues Need to agree on a minimum set of experiments to be carried out before the workshop ? (at least need to focus the presentations): –Impact of high resolution altimetry (2 to 4 altimeters) (Assimilation all, all 1 alt, all 2, 3 and 4 alt) –Impact of high resolution SST and GHRSST products (swath and analyzed products) –Impact of Argo (T and S) (alone and in combination with altimetry) (Assimilation all, all – Argo (T and S), all – Argo (S), all – altimetry)

IGST 12 – August 2007 – St Johns Proposed agenda (2 days) (to be discussed) 1.GODAE context – workshop objectives, 1 to 2 overview talks on OSSEs and OSEs (theory, use and limitations) (potential speakers ?) (2 h) 2.Altimetry (including MDT) (3h) 3.Argo and in-situ observing system (3 h) 4.Sea Surface Temperature/ GHRSST- PP (2 h) 5.Others (winds, salinity, gliders,…) (2 h) 6.Synthesis of results (3 h) 3-5 presentations per agenda item (2, 3, 4 and 5). Discussion (workshop style) => identify robust features, understand differences between assimilation systems, provide sound messages, etc Define workplan before the final conference Papers/presentations for final conference One rapporteur per session Synthesis of main results/recommendations by session rapporteur Identify main IGST contributions here !