Tropical instability waves (TIWs) are prominent seasonal features in both the equatorial Pacific and Atlantic Oceans. This work quantifies their role in modulating the distributions of nutrients and phytoplankton biomass. Using an eight year record of biannual ship observations along the Tropical Atmosphere Ocean (TAO) buoy array, cruise sections crossing...
Interactions between surface winds and meanders in mid-latitude sea surface temperature
(SST) fronts with horizontal length scales of 100-1000 km are investigated
from satellite observations and numerical simulations. Observations from the Sea-
Winds scatterometer on the QuikSCAT satellite show that the magnitude, direction,
curl, and divergence of the surface wind...
This thesis investigates the behavior of major inorganic nutrients (P, N, Si), trace metals (Mn, Fe), and alkaline-earth metals (Ba) within Tillamook Bay over seasonal cycles and under a range of river discharge conditions from October 1997 through December 1999. Located in the Pacific Northwest region, Tillamook Bay is an...
Two Autonomous Underwater Vehicle Gliders have alternated continuous sampling of a 45-nautical mile transect line (the Newport Hydrographic Line) across the Oregon continental shelf since April, 2006. Strong currents (>25cm/s) push the gliders off their trajectories as they survey this transect line, preventing them from sampling the historically occupied stations...
The local and remote sources of variability of the South Atlantic Ocean are investigated using a set of numerical experiments and satellite data. A global, eddy-permitting, numerical simulation is analyzed to investigate the dynamical links between the Antarctic Circumpolar Current (ACC) and the Malvinas Current (MC). The model results indicate...
We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...
Summertime, wind-driven upwelling off the Oregon coast delivers nutrient rich water to the surface that fuels the autotrophic production of particulate organic carbon (POC). This POC can be transported horizontally by fluid motions and vertically by sinking to the bottom where it can be entrained in the benthic boundary layer...
Instability and turbulence in sheared, salt-fingering favorable stratification are studied
using three-dimensional direct numerical simulations (DNS). Salt-fingering favorable
stratification is gravitationally stable, because the unstable vertical gradient of salinity
is stabilized by temperature (warm, salty over cool, fresh water-masses). Salt-fingering
instability can occur at the interface of these different water-masses....
Tide-topography coupling is important for understanding surface-tide energy loss, the intermittency of internal tides, and the cascade of internal-tide energy from large to small scales. Although tide-topography coupling has been observed and modeled for 50 years, the identification of surface and internal tides over arbitrary topography has not been standardized....
The organic content of the Columbia River suspended particulate matter (SPM) results from the input of autochthonous (phytoplankton) and allochthonous (terrestrial vascular plants) production. The contribution of these two sources appears seasonal and responds to factors such as rainfall, runoff, river flow, light and nutrients availability. While numerous studies have...