The effects of ice keels on the upper ocean are examined using a combination of
turbulence measurements and output from a large-eddy simulation (LES) model. Two
cases are examined, one during the winter when the under-ice boundary layer is relatively
deep (~20 m) and near the freezing point and a...
A sequence of direct simulations is used to study mechanisms for the growth of secondary
circulations and turbulence in stratified shear flows. Five cases are examined, of which four deliver
Holmboe waves as the primary instability and the fifth generates Kelvin-Helmholtz billows.
Secondary circulations range in strength from weak, laminar...
Renewable energy resources, such as wind, solar, and wave, have a number of advantages compared to traditional fossil fuels. Numerous studies attest to the physical potential for wave energy development in Oregon. In transitioning from conventional fossil fuel to alternative energy provision, citizen understanding of the global energy problems and...
The importance of leads, sea ice motion, and frazil ice on the wintertime ocean
Boundary layer was examined by using a large-eddy simulation turbulence model coupled to a
thermodynamic slab ice model. Coupling was achieved through exchange coefficients that
accounted for the differing diffusion rates of heat and salinity. Frazil...
High-resolution turbulence simulations are used to examine the importance of melt
pond geometry in setting pond growth rates and albedo. Modeling the circulation of
water in melt ponds using large-eddy simulation shows that both convective and windforced
conditions generate well-mixed ponds, suggesting that stratification is not a
significant factor in...
Ice-ocean heat exchange in polar leads was examined using a large-eddy simulation
model coupled to a slab ice model. Simulations were performed using an idealized square
domain for a range of lead sizes, surface wind stress (0.05–0.1 N/m²), and lead
temperature/salinity profiles. Particular emphasis was placed on understanding the role...
Direct numerical simulations of turbulence resulting from Kelvin–Helmholtz instability in stably
stratified shear flow are used to study sources of anisotropy in various spectral ranges. The set of
simulations includes various values of the initial Richardson and Reynolds numbers, as well as
Prandtl numbers ranging from 1 to 7. We...
When a stably stratified density interface is embedded in a region of strong velocity
shear, hydrodynamic instabilities result. Here we generalize the stratified shear layer
to allow an offset between the centre of the shear layer and the density interface. By
including this asymmetry, and keeping the density interface thin...
With little previous research on Astragalus peckii (Fabaceae), a state-listed
Threatened species in Oregon, I investigated three facets of its biology which are
integral to the conservation and management of the species. First, a four-year
demographic study of two large populations revealed increasing population growth at
one site (Chiloquin) and...
Tuberculoѕiѕ (TB) iѕ a number one killer among treatable infectious diseases. It is caused by the pathogenic bacterium Mycobacterium tuberculoѕiѕ that primarily affects the lungѕ. It infects one third of the world population and kills approximately 2 million people each year (based on WHO report). Drug-reѕiѕtant TB haѕ become a...