CLOSURE DISCUSSIONS AND OUTLOOK

In plenary session on Friday morning, the WG reports were received and discussed. It was found that the immediate main objective of a WOCE/AIMS synthesis activity, i.e. the production of atlases and maps that can serve as basis for future model and inverse analysis studies was considered well under way based on the activities presented in WG1. Computing was identified as the largest practical problem for synthesis. Internationally, the lack of adequate supercomputer support has reached critical dimensions. As to the model development and parameterisation reviewed by WG2, active group co-operations are under way and co-ordinated activities continue in the WOCE Ocean Model Development WG (chaired by C. Böning). The model comparisons and evaluations recommended by WG3 were endorsed and the need expressed by modelling participants of WG3 for establishing decadal ocean observations was noted. WG4 recommendations were developed from existing plans and expanded based on requirements derived from Workshop topics with the intent to merge this into the papers to be prepared for the OceanObs’99 Conference in St. Raphael. In relation to future observations, some participants expressed concern about the fact that a data management structure for such observations still needs to be established. It was emphasised that existing WOCE structures should be reviewed and maintained if suitable for CLIVAR/GOOS purposes.

A number of group cooperations for model-observation synthesis were established during the Workshop, in particular on Labrador Sea convection and resulting large-scale effects on the overturning circulation. Regarding future observations, a group meeting was organised on Wednesday, 25th August, by Y. Desaubies to work out a co-ordinated proposal for profiling float deployments within ARGO in the context of the EU 5^th Framework funding initiative. Another such EU proposal initiative discussed by members of the Nordic WOCE group, and other potential partners, was on the exchange between the Atlantic and the Norwegian/Iceland Sea.

Several possible milestones for more formal future cooperations and interactions were discussed such as special sessions at AGU or EGS and presentations in relevant sessions of the upcoming Ocean Sciences Meeting.

Concerning focused publications on Workshop topics, participants were made aware that a special issue of JPO on Labrador Sea convection is being assembled, but other possible options for collections of future synthesis papers were also discussed.

PROGRAMME

Monday, 23 August 9.00 Welcome

Mr Norbert Gansel, Oberbürgermeister of Kiel Prof. Peter Lemke, Director IfM Kiel,

Dr John Gould, Director International WOCE/CLIVAR Office Workshop Outline

F. Schott, Chairman, Scientific Organising Committee

10.00 Session 1: North Atlantic decadal variability and the WOCE period Co-Chairs: C. Böning and F. Schott

Interdecadal variability in coupled GCMs: Model results versus observations (M. Latif) 10.30 Coffee Break

11.00 Decadal variability of water masses and circulation in the subpolar North Atlantic (R. Curry) Decadal variability of water masses, overturning and heat transport across 48°N (P.

Koltermann)

Decadal variability in the North Atlantic: relationships between overturning and sea level variations (S. Hakkinen)

Can low frequency variability internal to the atmosphere drive significant interdecadal variability in the ocean and in coupled ocean-atmosphere models? (R. Greatbatch)

12.40 Lunch

14.00 Is a steady-state ocean circulation still a useful framework for understanding? (C. Wunch) Discussion session 1 and posters info

15.30 Coffee Break 16.00 Posters info

16.30 Posters Presentations

18.00 Ice Breaker Party, RV Alkor, IfM Dock Tuesday, 24 August

9.00 Session 2: North Atlantic circulation, pathways and water mass distributions from WOCE observations, altimetry and model results

Co-Chairs: R. Molinari and P. Schlosser

Upper-layer circulation within and north of the Gulf Stream (L. Talley) Upper-layer circulation in high-resolution models (A.-M. Treguier) Gulf Stream Modelling (E. Chassignet)

10.15 Coffee Break

10.45 Modelling the DWBC and recirculation (M. Kawase)

Observations of Subtropical/Tropical Deep Circulation (R. Fine)

Decadal variability in the North Atlantic: relationships between overturning and sea level variations (S. Hakkinen)

Coupling to the tropics (J. Carton) Discussion session 2 and posters info 12.30 Lunch

14.00 Session 4a: North Atlantic water mass modification processes: Overflows Co-Chairs: P. Killworth and R. Käse

Modelling flows through sills and straits and related large scale effects in models (P. Killworth) Review of the exchange between the Mediterranean and the Atlantic through the Straits of Gibraltar (H. Bryden)

Some results from long-term observations of the deep-water flux through the Faroe-Bank Channel (P. Lundberg, K. Borenäs, B. Hansen, I. Lake and S. Østerhus)

15.15 Coffee Break

15.45 New measurements of the velocity structure of the Denmark Strait Overflow currents and eddies (J. Girton)

Discussion session 4a and posters info 16.30 Posters Presentations

Wednesday, 25 August

9.00 Session 3: Thermohaline overturning and flux divergences Co-Chairs: H. Bryden and C. Wunsch

Overview on the problem of flux divergences (C. Wunsch)

Fluxes heat, freshwater, oxygen and nutrients in the North Atlantic from a new global inversion (A. Ganachaud)

Section inverse analysis results (H. Mercier) 10.15 Coffee Break

10.45 Model-derived meridional mass and heat transports and their variability (J. Marotzke) The export of Atlantic water to the Nordic Seas (B. Hansen, S. Østerhus, B. Turrell and S. Jonsson)

Surface heat fluxes and wind stress forcing in the North Atlantic (S. Josey, E. Kent and P. Taylor)

Discussion session 3 and posters info 12.30 Lunch

14.00 Session 4b: Labrador Sea convection Co-Chairs: M. Visbeck and F. Schott

Labrador Sea water mass variability during the WOCE period (A. Clarke) The deep convection experiment of winter 1996/97 (M. Visbeck)

Variability of deep convection and boundary circulation 1996–98 (U. Send, F. Schott, D. Kindler, C. Mertens and J. Fischer)

15.15 Coffee Break

15.45 Labrador Sea convection in models and relation to THC variability (E. Chassignet) Discussion session 4b and posters info

16.30 Posters Presentations Thursday, 26 August

9.00 Session 4c: Deep mixing and role of topography Chair: P. Malanotte-Rizzoli

Modelling the role of topographic interaction (R. Käse)

Synthesis of the Deep Basin tracer release experiment (L. St. Laurent) Discussion session 4c

10.15 Changes to working groups 10.30 Coffee Break

11.00 Working groups, batch I 13.00 Lunch

14.00 Session 4d: Thermocline ventilation Chair: D. Marshall

Physics of thermocline ventilation (D. Marshall)

The use of tracers to study thermocline ventilation (W. Jenkins) Discussion session 4d

15.15 Coffee Break

15.45 Working Groups, batch II Friday, 27 August

8.30 Working Groups continued

9.30 Working Groups reports to plenary 10.30 Coffee Break

11.00 Plenary Discussion, conclusion 13.00 Close of North Atlantic Workshop

14.30 Workshop report activities, Synthesis group co-operation continued