Abstract

Interacting plumes in a rotating environment: The special case of a single plume

Turbulent buoyant plumes are prolific in geophysical and environmental flows, and on the largest geophysical scales their development can be affected by rotation. Previous studies have shown that classical plume models can predict the early-time development of rotating plumes, although their long term behaviour is less well understood. This talk will outline some of the difficulties involved in performing laboratory studies of plumes in rotating environments and will present results from experiments performed during the WHOI Geophysical Fluid Dynamics Program. These experiments highlight interesting features that arise when point source wall plumes are generated in the presence of ambient rotation.

The dynamical system of mixing layers – Jeremy Parker

Situations in which a light fluid moves above a dense fluid are ubiquitous in the environment, and are one of the classical examples of an instability in fluid dynamics. In particular, they are thought to be responsible for much of the mixing that occurs in the ocean, with important consequences for the modelling of the global ocean circulation and understanding of climate change. An abstract understanding of physical situations like these mixing layers, the so-called “dynamical systems picture” of fluid mechanics, permits a high level understanding of the behaviour as a whole. Different computational strategies are discussed to understand mixing layers through the lens of dynamical systems, including Direct-Adjoint Looping, an optimisation technique, and Newton-Krylov iteration to find exact coherent solutions to the system.