Lateral and Vertical Mixing in Marginal Seas (2001-2002). Topographic Influence on Small-Scale Oceanic Dynamics (1999-2000). Mixing, Fine-Structure and Internal Waves Near Shallow-Summit Seamounts (1997-1998)

摘要

Small, fine, and meso-scale structures in deep and littoral oceans were studied using field observations, data analysis and numerical simulations. The archives of data collected by Russian oceanographers were scrutinized for data quality and posted on the web for the use of international community. Three new trans-Atlantic cruises focusing on marginal zones were organized in collaboration with Russian and Spanish scientists. The influence of topography on oceanic flows was investigated on shelves and continental slopes, around seamounts and near submarine ridges. The excessive energy of internal tides produces enhanced mixing in the pycnocline at a distance up to 1000 km from the topography. The extensive turbulent 'columns' were discovered above the seamount summits; the diffusivities exceed the background values by two orders of magnitude. Study of shelf mixing turbulence and internal waves in semi-enclosed basins showed that short internal waves generated at the tidal shelf break of the Peter the Great Bay can produce vertical diffusivities in the pycnocline up to 10(exp-3) sq m/s, which is about an order of magnitude higher than on the Black Sea non-tidal shelf. Numerical modeling was focused on the formation of step-like structure in the thermocline due to boundary forcing. A new parameterization for the patch turbulence was suggested using the normalized Thorpe scale.