Time-dependent downwelling on the Oregon continental shelf is studied with a two-dimensional approximation, that is, spatial variations across shelf and with depth, using the Blumberg-Mellor, finite-difference, stratified, hydrostatic, primitive equation model. The time-dependent response of a coastal ocean at rest to constant, downwelling-favorable wind stress is examined. Topography and stratification...
Model studies of two-dimensional, time-dependent, wind-forced, stratified downwelling circulation on the continental shelf have shown that the near-bottom offshore flow can develop time- and space-dependent fluctuations involving spatially periodic separation and reattachment of the bottom boundary layer and accompanying recirculation cells. Based primarily on the observation that the potential vorticity...
An inertial subrange was found in spectra calculated from vertical profiles of temperature gradient recorded in the bottom boundary layer of the Oregon shelf. Spectra were calculated for 53-cm vertical segments. An ensemble average of those spectra that were fully resolved and had high Cox number was compared to the...
New K-Ar age determinations on
basalts, basaltic andesites, and ash flow
tuffs from the central Western Cascades in
Oregon range in age from 32 to 3 Ma. The
ages decrease from west to east and with
increasing elevation. Volcanism has been
continuous throughout the evolution of the
Western Cascades, with...
Previously published physical and biological data document a zonally oriented frontal region within the California Current system separating colder and more eutrophic water north of ≈33°N from warmer; more stratified, and oligotrophic water farther to the south. Satellite images of phytoplankton pigment from the coastal zone color scanner from 1979-1983...
A 5-year time series of coastal zone color scanner imagery (1980-1983, 1986) is used to examine
changes in the large-scale pattern of chlorophyll pigment concentration coincident with the spring
transition in winds and currents along the west coast of North America. The data show strong
interannual variability in the timing...
Two methods of estimating surface velocity vectors from advanced very high resolution radiometer (AVHRR) data were applied to the same set of images and the results were compared with in situ and altimeter measurements. The first method used and automated feature –tracking algorithm and the second method used an inversion...
An Eulerian analysis for wave forcing of three-dimensional (3D) wave-averaged mean
circulation in the surf zone is presented. The objective is to develop a dynamically
consistent formulation for applications in a 3D primitive equation model. The analysis is
carried out for the case of shallow-water linear waves interacting with wave-averaged...
Seamounts are windows into the deep Earth that are helping to
elucidate various deep Earth processes. For example, thermal and mechanical
properties of oceanic lithosphere can be determined from the flexing of oceanic
crust caused by the growth of seamounts on top of it. Seamount trails also are
excellent recorders...
The drastic reduction in cattle prices with constantly rising costs
of production emphasizes the value of superior genetic material. Although the costs of progeny testing have risen with other production costs, the positive identification of superior genetic material can only be determined by progeny testing.
Seventy-six heifers and 312 steers...