Experience:

 

Coastal Ocean Institute Postdoctoral Scholar,  Woods Hole Oceanographic Institution, 2006-2007.  Physical Oceanography and Biology Departments.

My research focuses on problems at the interface of fluid dynamics and biology that are relevant to coastal regions.  The goal is to understand the physical processes, including currents, waves, and turbulence, that are responsible for transporting water, sediment, chemicals, and biological organisms through rivers, wetlands, and the coastal ocean.  These flows on scales from centimeters to a kilometer are generally unresolved by physical ocean models, yet are essential to the ecology and biogeochemistry of the ocean.  One line of research deals with the complex turbulence and organized flow structures found in aquatic vegetation like wetlands and seagrass meadows, which influence the equilibrium and evolution of these ecosystems.  The plants strongly affect the flow of water, sediments, and nutrients, which can in turn affect the population dynamics of the ecosystem in a positive feedback.  A related interest is in the structure of boundary layer turbulence at the ocean bottom and its influence on biogeochemical transfers at the sediment-water interface.  The seabed is complex due to a variety of benthic structures, both geologic and biological in origin, from course gravel and cobbles to algal mats and coral reefs.  This topographic complexity creates strong instabilities and enhanced turbulent transfers of material between the bed and the water column.  

 

Another line of research interest is on gravity currents, internal waves, and shear flows in stratified fluids.  One project is on the flow of either very dense or very light water into a stably stratified ocean environment which can generate nonlinear internal waves of significant amplitude.  These waves can be an important shoreward transport mechanism for larval stages of marine organisms.  Another project deals with mixing in stratified shear flows formed when two estuarine water masses with different salinity or temperature flow past each other.  Instabilities are formed by horizontal shear and then strengthened into intense vortices by the gravitational collapse of the horizontal density gradient.  These problems are studied using a combination of laboratory experiments and analytical and numerical modeling approaches.