Hickey Barbara M.

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Hickey
First Name
Barbara M.
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  • Dataset
    CT Drifter measurements from multiple R/V Wecoma cruises in the Northeast Pacific coastal waters off states of Washington and Oregon from 2004 to 2006 (RISE project)
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-04-28) Hickey, Barbara M.
    This dataset includes CT Drifter measurements from multiple cruises on the R/V Wecoma in the Northeast Pacific coastal waters off states of Washington and Oregon from 2004 to 2006. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3244
  • Article
    Regional impact of submarine canyons during seasonal upwelling
    (John Wiley & Sons, 2014-02-12) Connolly, Thomas P. ; Hickey, Barbara M.
    A numerical model of the northern California Current System along the coasts of Washington and British Columbia is used to quantify the impact of submarine canyons on upwelling from the continental slope onto the shelf. Comparisons with an extensive set of observations show that the model adequately represents the seasonal development of near-bottom density, as well as along-shelf currents that are critical in governing shelf-slope exchange. Additional model runs with simplified coastlines and bathymetry are used to isolate the effects of submarine canyons. Near submarine canyons, equatorward flow over the outer shelf is correlated with dense water at canyon heads and subsequent formation of closed cyclonic eddies, which are both associated with cross-shelf ageostrophic forces. Lagrangian particles tracked from the slope to midshelf show that canyons are associated with upwelling from depths of ∼140–260 m. Source depths for upwelling are shallower than 150 m at locations away from canyons and in a model run with bathymetry that is uniform in the along-shelf direction. Water upwelled through canyons is more likely to be found near the bottom over the shelf. Onshore fluxes of relatively saline water through submarine canyons are large enough to increase volume-averaged salinity over the shelf by 0.1–0.2 psu during the early part of the upwelling season. The nitrate input from the slope to the Washington shelf associated with canyons is estimated to be 30–60% of that upwelled to the euphotic zone by local wind-driven upwelling.
  • Article
    Seasonal and interannual oxygen variability on the Washington and Oregon continental shelves
    (John Wiley & Sons, 2015-02-05) Siedlecki, Samantha A. ; Banas, Neil S. ; Davis, Kristen A. ; Giddings, Sarah N. ; Hickey, Barbara M. ; MacCready, Parker ; Connolly, Thomas P. ; Geier, S.
    The coastal waters of the northern portion of the California Current System experience a seasonal decline in oxygen concentrations and hypoxia over the summer upwelling season that results in negative impacts on habitat for many organisms. Using a regional model extending from 43°N to 50°N, with an oxygen component developed in this study, drivers of seasonal and regional oxygen variability are identified. The model includes two pools of detritus, which was an essential addition in order to achieve good agreement with the observations. The model was validated using an extensive array of hydrographic and moored observations. The model captures the observed seasonal decline as well as spatial trends in bottom oxygen. Spatially, three regions of high respiration are identified as locations where hypoxia develops each modeled year. Two of the regions are previously identified recirculation regions. The third region is off of the Washington coast. Sediment oxygen demand causes the region on the Washington coast to be susceptible to hypoxia and is correlated to the broad area of shallow shelf (<60 m) in the region. Respiration and circulation-driven divergence contribute similar (60, 40%, respectively) amounts to the integrated oxygen budget on the Washington coast while respiration dominates the Oregon coast. Divergence, or circulation, contributes to the oxygen dynamics on the shelf in two ways: first, through the generation of retention features, and second, by determining variability.
  • Article
    Coastal trapped waves, alongshore pressure gradients, and the California Undercurrent
    (American Meteorological Society, 2014-01) Connolly, Thomas P. ; Hickey, Barbara M. ; Shulman, Igor ; Thomson, Richard E.
    The California Undercurrent (CUC), a poleward-flowing feature over the continental slope, is a key transport pathway along the west coast of North America and an important component of regional upwelling dynamics. This study examines the poleward undercurrent and alongshore pressure gradients in the northern California Current System (CCS), where local wind stress forcing is relatively weak. The dynamics of the undercurrent are compared in the primitive equation Navy Coastal Ocean Model and a linear coastal trapped wave model. Both models are validated using hydrographic data and current-meter observations in the core of the undercurrent in the northern CCS. In the linear model, variability in the predominantly equatorward wind stress along the U.S. West Coast produces episodic reversals to poleward flow over the northern CCS slope during summer. However, reproducing the persistence of the undercurrent during late summer requires additional incoming energy from sea level variability applied south of the region of the strongest wind forcing. The relative importance of the barotropic and baroclinic components of the modeled alongshore pressure gradient changes with latitude. In contrast to the southern and central portions of the CCS, the baroclinic component of the alongshore pressure gradient provides the primary poleward force at CUC depths over the northern CCS slope. At time scales from weeks to months, the alongshore pressure gradient force is primarily balanced by the Coriolis force associated with onshore flow.