NANOOS Visualization System Trinidad Head Glider Portal - Northwest Association of Networked Ocean Observing Systems
Original (non-English) name
Acronym
NVS Trinidad Head Glider Portal - NANOSS
Citation
Abstract
This research addresses a fundamental question in coastal oceanography: What are the relative contributions of the interaction between wind-driven flow and bottom topography, and offshore source water variations, to event-scale, seasonal and interannual variations in water properties and flow dynamics over the continental shelf and slope? While much has been learned about flow-topography interaction during process-oriented cruises of up to one-month duration, these provide only a few realizations of the weather-band (2-10 days) variability and lack seasonal coverage. Moored observations, while more continuous and sometimes year-round, are rarely of sufficient horizontal resolution to describe the interaction of coastal fronts and jets with topographic features. We are using year-round Autonomous Underwater Vehicle Glider (AUVG)-based observations, together with remotely sensed data, to understand the annual cycle of flow-topography interaction between shelf flows and a submarine bank. A northern E-W glider section, north of Heceta Bank, Oregon, is along the Newport Hydrographic (NH) Line (44 39.1'N), for which there is a substantial historical data base. A second E-W glider line, south of Heceta Bank off the Umpqua River (43 45'N), sampled in combination with the NH line will allow us to quantify the year-round, time-dependent cross-shelf flux of water and the material it contains. We started pilot glider operations on the NH line in summer 2005, while routine, nearly continuous sampling began in April 2006. We expanded AUVG sampling in summer 2008 to include concurrent sampling of both E-W sections using two gliders. We are using the glider data, together with meteorological and satellite data and numerical models of wind-driven shelf flows, to understand the dynamics and seasonal variability of flow-topography interaction. By sampling over multiple years in a region with significant interannual variability (El Niño, Pacific Decadal Oscillation), we are exploring the modulation of flow-topography interaction byinterannual variability.