A Laboratory Study of Wave-Affected Turbulence in a Flexible Canopy: Transport in a Giant Kelp Forest

Stanford University, Stanford CA

Investigators

Abstract

ABSTRACT PROPOSAL NO.: CTS-0335346 PRINCIPAL INVESTIGATORS: JEFFREY R. KOSEFF INSTITUTION: STANFORD UNIVERSITY A LABORATORY STUDY OF WAVE-AFFECTED TURBULENCE IN A GIANT KELP FOREST The objectives are to study fluid dynamics and transport associated with the rich ecosytstem environment of kelp forests in the ocean. Within these systems, hydrodynamics govern nutrient availability to macro algae, the delivery of food particles to invertebrates, the uptake of dissolved gases, nutrients and organic carbon by the kelp forest community, the dispersal of planktonic spores within the kelp communities, and their settlement in the coastal zone. This study will augment an ongoing field program with a set of critically needed laboratory experiments focusing on problems that cannot be adequately resolved in the field. A variety of optical diagnostic techniques will be employed to investigate the flow field in a model kelp forest in the presence of waves and current. These techniques will allow direct measurement of velocities and scalar fluxes, enabling characterization of mixing processes, investigation of the spatial variability of the flow and examination of the dependence of mixing rates and turbulence intensity on kelp forest structure. This flow configuration presents an excellent opportunity to not only understand how kelp canopies affect the momentum and energy transfer from waves into turbulence in the water column, but also to further explore wave-bottom boundary interactions in the presence of articulating roughness elements which potentially generate turbulence in the water column itself. The project will provide research training for students in an interdisciplinary research project involving fluid mechanics and physical oceanography. The investigators will continue their practice of involving undergraduates in the research through Stanford's REU program, which has been successful in recruiting diverse students from different majors and underrepresented groups to participate in research. This research program will enhance the infrastructure for research, by further developing the laboratory facility for studying wavy flows; and for education, by using these facilities for hands-on experimentation in classes in fluid mechanics and physical oceanography. The investigators already work with the media and science writers to convey research discoveries to the public, and plan to continue such outreach activities.