Export 4 results:
Sort by: Author Title Type [ Year  (Desc)]
Adams, KA, Hosegood P, Taylor JR, Sall J-B, Bachman S, Torres R, Stamper M.  2017.  Frontal Circulation and Submesoscale Variability during the Formation of a Southern Ocean Mesoscale Eddy. Journal of Physical Oceanography. 47:1737–1753.   10.1175/JPO-D-16-0266.1   AbstractWebsite

AbstractObservations made in the Scotia Sea during the May 2015 Surface Mixed Layer Evolution at Submesoscales (SMILES) research cruise captured submesoscale, O(1–10) km, variability along the periphery of a mesoscale O(10–100) km meander precisely as it separated from the Antarctic Circumpolar Current (ACC) and formed a cyclonic eddy {\~{}}120 km in diameter. The meander developed in the Scotia Sea, an eddy-rich region east of the Drake Passage where the Subantarctic and Polar Fronts converge and modifications of Subantarctic Mode Water (SAMW) occur. In situ measurements reveal a rich submesoscale structure of temperature and salinity and a loss of frontal integrity along the newly formed southern sector of the eddy. A mathematical framework is developed to estimate vertical velocity from collocated drifter and horizontal water velocity time series, under certain simplifying assumptions appropriate for the current dataset. Upwelling (downwelling) rates of O(100) m day−1 are found in the northern (southern) ed...

Bachman, SD, Taylor JR, Adams KA, Hosegood PJ.  2017.  Mesoscale and Submesoscale Effects on Mixed Layer Depth in the Southern Ocean. Journal of Physical Oceanography. :JPO–D–17–0034.1.   10.1175/JPO-D-17-0034.1   AbstractWebsite

AbstractSubmesoscale dynamics play a key role in setting the stratification of the ocean surface mixed layer and mediating air-sea exchange, making them especially relevant to anthropogenic carbon uptake and primary productivity in the Southern Ocean. In this paper a series of offline-nested numerical simulations is used to study submesoscale flow in the Drake Passage and Scotia Sea regions of the Southern Ocean. These simulations are initialized from an ocean state estimate for late-April 2015, with the intent to simulate features observed during the Surface Mixed Layer at Submesoscales (SMILES) research cruise which occurred at that time and location. The nested models are downscaled from the original state estimate resolution of 1/12° and grid spacing of about 8 km, culminating in a submesoscale-resolving model with a resolution of 1/192° and grid spacing of about 500 m. The submesoscale eddy field is found to be highly spatially variable, with pronounced “hotspots” of submesoscale activity. These area...

Adams, KA, Barth JA, Shearman KR, Adams KA, Barth JA, Shearman KR.  2016.  Intraseasonal Cross-Shelf Variability of Hypoxia along the Newport, Oregon, Hydrographic Line. Journal of Physical Oceanography. 46:2219–2238.   10.1175/JPO-D-15-0119.1   AbstractWebsite

AbstractObservations of hypoxia, dissolved oxygen (DO) concentrations {\textless} 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 sequ...

Adams, KA, Barth JA, Chan F.  2013.  Temporal variability of near-bottom dissolved oxygen during upwelling off central Oregon. Journal of Geophysical Research: Oceans. 118:4839–4854.   10.1002/jgrc.20361   AbstractWebsite