@article {RN35,
	title = {Intraseasonal Cross-Shelf Variability of Hypoxia along the Newport, Oregon, Hydrographic Line},
	journal = {Journal of Physical Oceanography},
	volume = {46},
	number = {7},
	year = {2016},
	pages = {2219-2238},
	type = {Journal Article},
	abstract = {Observations of hypoxia, dissolved oxygen (DO) concentrations < 1.4 ml L-1, off the central Oregon coast vary in duration and spatial extent throughout each upwelling season. Underwater glider measurements along the Newport hydrographic line (NH-Line) reveal cross-shelf DO gradients at a horizontal resolution nearly 30 times greater than previous ship-based station sampling. Two prevalent hypoxic locations are identified along the NH-Line, as is a midshelf region with less severe hypoxia north of Stonewall Bank. Intraseasonal cross-shelf variability is investigated with 10 sequential glider lines and a midshelf mooring time series during the 2011 upwelling season. The cross-sectional area of hypoxia observed in the glider lines ranges from 0 to 1.41 km2. The vertical extent of hypoxia in the water column agrees well with the bottom mixed layer height. Midshelf mooring water velocities show that cross-shelf advection cannot account for the increase in outer-shelf hypoxia observed in the glider sequence. This change is attributed to an along-shelf DO gradient of -0.72 ml L-1 over 2.58 km or 0.28 ml L-1 km-1. In early July of the 2011 upwelling season, near-bottom cross-shelf currents reverse direction as an onshore flow at 30-m depth is observed. This shoaling of the return flow depth throughout the season, as the equatorward coastal jet moves offshore, results in a more retentive near-bottom environment more vulnerable to hypoxia. Slope Burger numbers calculated across the season do not reconcile this return flow depth change, providing evidence that simplified two-dimensional upwelling model assumptions do not hold in this location.},
	keywords = {Circulation/Dynamics, Coastal flows, Upwelling/downwelling},
	issn = {0022-3670},
	doi = {10.1175/Jpo-D-15-0119.1},
	author = {Adams, K. A. and Barth, J. A. and Shearman, R. K.}
}
