formation. Okada presented results of a non-hydrostatic model: properties of the dense water transported into the interior during convection depend on the size, distribution, and movement of leads and polynyas. This dependency should be investigated further to parameterize dense water formation appropriately in a coarse-grid model with simpler physics.
Ice mechanics is not only important for ice drift, but also for dense water formation through brine rejection, which often occurs in open leads and coastal polynyas.Ukita suggested that ice rheology should be examined further, so that both the mean and variability of ice movement are simulated accurately for ice formation. Kakuta showed that SAR images were useful for estimating ice movement at weekly intervals.
The second part of the third day consisted of analyses of climatological data sets.Wang obtained the ENSO and NAO patterns, which were considered to influence the Arctic climate. Minobe focused on the North Pacific and North America, showing oscillations at periods of about 20 and 50 years. The recent finding of warming in the Atlantic layer might be related to the dominant climate variability. These results suggest that we should be aware how representative data collected during a particular field experiment are.
Together these presentations suggested that: (1) Process-oriented field experiments are badly needed, and (2) Collaboration between modelers and field experimentalists is necessary. The result will be improved understanding of processes, more appropriate parameterization, an improved ability to verify models, and optimally designed field experiments.
Final Plenary Discussion
Several important themes of the workshop were emphasized in the final discussion. One of these was the need to consider the interactive and two-way nature of the shelf-slope-basin system, since buoyancy and material fluxes are directed both onto and off the shelf. For example, while there must be on-shelf fluxes to compensate for dense shelf outflows, we do not know how this is accomplished. Another theme was the need to account for the considerable variety of processes that likely are involved in shelf-basin interaction, ranging from frontal instabilities to particulate fluxes. Which processes are in fact important to a particular problem? The shelf break and slope were recognized as especially critical areas, with their steep topography, variable stratification, and strong boundary current. A third theme was the connection between shelf processes and observed large-scale changes in the interior ocean, e.g., the recent changes within the
