Lucas, L. V. U.S. Geological Survey, llucas@usgs.gov
Cloern, J. V. U.S. Geological Survey, jecloern@usgs.gov
Koseff, J. R. Stanford University, Dept. of Civil and Environmental Engineering, koseff@ce.stanford.edu
Monismith, S. G. Stanford University, Dept. of Civil and Environmental Engineering, monismit@ce.stanford.edu

 
PHYSICAL INFLUENCES ON BLOOM DEVELOPMENT IN SHALLOW TIDAL SYSTEMS: WHAT TIMESCALES ARE IMPORTANT?
 
Phytoplankton bloom development depends on numerous interacting processes. Superposed on biological and chemical influences---and sometimes at the root of them---physics controls the conditions to which phytoplankton are subjected, both by transporting phytoplankton through a variety of subenvironments and by modifying conditions over time within each subenvironment. This web of influences on bloom dynamics is especially complicated in systems which are subjected to a variety of physical forcings such as tides, river flow, and wind, whose effects vary over timescales of seconds to years. For example, tidal effects include turbulent mixing, largescale dispersion, water column shallowing and deepening, tidal scale advection, and daily-weekly scale residual transport, the intensity of which may modulate with the fortnightly spring/neap cycle as well as over the annual equinox-solstice cycle. Clearly, not all such scales of variability can currently be measured or modeled, especially when large spatial domains are considered. Furthermore, not all scales of variability are significant in all systems. Thus, choices must be made regarding which scales to resolve. Based on a depth-averaged numerical model, we identify short and long timescale physical-biological linkages in shallow tidal systems and describe conditions under which they are critical to bloom development.
 
Day: Friday, Feb. 5
Time: 09:00 - 09:15am
Location: Eldorado Hotel
 
Code: SS42FR0900E