MacIntyre, S. University of California, Santa Barbara,
Alldredge, A. University of California, Santa Barbara,

Abundance of marine snow was determined using a profiling camera system in East Sound, Washington, in June 1998. Concurrent profiles of the intensity of turbulence were obtained with a temperature-gradient microstructure profiler. These observations were made as part of the Thin Layers Experiment designed to document the layering of biological materials in a stratified water column exposed to substantial shear from tidally induced currents and occasional wind induced mixing. Pronounced layering of marine snow occurred just below a strong pycnocline. Turbulent intensity was low (epsilon < 10^(-8) m^2 s^(-3)). The importance of shear to layer formation was observed when fluoresceine dye, introduced over a 1-m vertical layer at 9-10 m depth, was initially tilted and subsequently spread into a thin, horizontal layer. During this time, rates of energy dissipation were less than 10^(-9) m^2 s^(-3) indicating little vertical mixing. Layering of marine snow and acoustic scatterers occurred within a pycnocline immediately below a shallow upper mixed layer with moderate levels of turbulence. Our results again indicate that layers of marine snow are associated with density gradients and moderate to low levels of turbulence.
Day: Tuesday, Feb. 2
Time: 11:00 - 11:15am
Location: Hilton of Santa Fe
Code: SS05TU1100H