Prof. Sergey Prants

Pacific Oceanological Institute, Vladivostok, Russia

Email: prants@poi.dvo.ru

Research interests: Ranging from the study of Hamiltonian and dissipative chaos with atoms in optical lattices and cavities to the study of wave and ray chaos in the underwater sound channel in the ocean and now to different aspects of ocean dynamics. My current primary research interests concern the study of transport and mixing processes in the ocean from theoretical, numerical, and observational viewpoints using Lagrangian approach and tools from dynamical systems theory. It provides, in particular, a deeper insight in dynamics and life cycles of Lagrangian fronts and eddies in satellite-derived and OCM velocity fields at sub- and mesoscales in the ocean, mainly in the Northwestern Pacific and Asian marginal seas.

Fronts and eddies in the ocean from the Lagrangian point of view

Abstract

Recently elaborated Lagrangian tools are applied to identify and track fronts and mesoscale eddies in the satellite- and OCM-derived velocity fields. The notion of a Lagrangian front was introduced to define a boundary between water masses with different Lagrangian properties. Maximal gradients of common quantities are known to indicate hydrological fronts (thermal, salinity and density ones) which are often connected with each other. However, one may introduce a number of specific Lagrangian indicators and compute their maximal gradients in a given velocity field. For example, converging water masses could have the same temperature or salinity and do not show a thermal or salinity front, but some Lagrangian characteristics of those water masses could be different to create a Lagrangian front. We show how to identify Lagrangian fronts and document the life story of mesoscale eddies by inspecting daily computed Lagrangian maps for different indicators. The methodology is applied to find correlations of Lagrangian fronts and eddies with fishing grounds in the northwestern Pacific.