@article {RN84,
	title = {Surfzone State Estimation, with Applications to Quadcopter-Based Remote Sensing Data},
	journal = {Journal of Atmospheric and Oceanic Technology},
	volume = {35},
	number = {10},
	year = {2018},
	pages = {1881-1896},
	type = {Journal Article},
	abstract = {A one-dimensional variational data assimilation (1DVar) method is presented based on the depth- and time-averaged alongshore-uniform surfzone wave and current equations, for simultaneous estimation of three uncertain variables: bathymetry, incident wave boundary conditions, and bed roughness. The method is validated using twin tests and in situ field observations, and its results are shown to be comparable to those of an existing ensemble-based bathymetry inversion technique. Unlike existing techniques, the ability to simultaneously estimate boundary conditions and bed roughness along with bathymetry also means the 1DVar method can produce full state estimates without the requirement for additional supporting measurements (e.g., direct measurements of the incident waves). A proof-of-concept field application is shown using observations collected from an unmanned quadcopter sensor package that measures surfzone wave height from a fixed-beam lidar range finder, and time-averaged longshore current from particle image velocimetry of drifting surface foam.},
	keywords = {Bayesian methods, Coastal flows, Data assimilation, Inverse methods, Numerical analysis/modeling, Variational analysis},
	issn = {0739-0572},
	doi = {10.1175/JTECH-D-17-0205.1},
	url = {https://doi.org/10.1175/JTECH-D-17-0205.1},
	author = {Wilson, Gregory and Berezhnoy, Stephen}
}
@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.}
}
