Faculty Candidate Seminar - Drew Lucas

03/31/2016 - 11:00am

DATE:     March 31st
(& chalk talk 4/1 in NH101 at 2:00pm)

LOCATION:  11:00am Engineering Bldg Unit 2, room 479 (main campus)
SPEAKER: Drew Lucas, Ph.D.

TITLE:   Fronts, bores, and plumes: observations of the shared dynamics of shallow oceanic boundary layers and buoyant effluent discharges

Internal waves and submesoscale processes drive variability in the oceanic boundary layer and thus are critical to air/sea fluxes and biogeochemical cycling. These small-scale dynamics are also fundamental to the evolution of buoyant effluent plumes discharged from wastewater treatment and hydroelectric plants.  Although the physics governing their evolution is well characterized from a theoretical perspective, gathering evidence to test theoretical predictions, validate high-resolution numerical models, assess their influence on air/sea interactions and biogeochemical fluxes, or manage their impact on coastal water quality requires difficult-to-obtain observations. In this seminar, I will describe a set of tools developed to address this common problem-space in oceanography and environmental fluid mechanics, and highlight results achieved to date.  For example, observations of the salinity-stratified Bay of Bengal, gathered by a drifting array of wave-powered profiling vehicles and shipboard rapid-profiling systems, indicate that the extremely sharp, shallow fronts characteristic of the region are unbalanced by rotation, and instead propagate as gravity currents. This mechanism for open-ocean restratification may play an important role in the control of upper ocean structure in the region, and perhaps other low-latitude systems, with important consequences for patterns of atmospheric convection and the development and propagation of intraseasonal oscillations in the southwest monsoon. Such dynamical processes also underlie the evolution of buoyant effluent plumes, and thus control the dispersal of pollutants contained within them. Utilizing a similar observational approach, I will show how physical variability in ambient (receiving) waters influences the disposition and fate of the buoyant plumes discharged from wastewater treatment and hydroelectric plants, allowing for an assessment of the validity of scaling arguments used in plume categorization and modeling. I will conclude the talk with directions for my future research in the fields of oceanographic instrumentation design, environmental fluid mechanics, and oceanography, highlighting the fertile ground for collaborative, interdisciplinary research in those fields, and others within the purview of the Jacobs School of Engineering and Scripps Institution of Oceanography.
For more information on this event, contact: 
Leslie Costi
Event Calendar: 
Engineering Bldg Unit 2, room 479 (main campus)