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2005
Falkner, KK, Steele M, Woodgate RA, Swift JH, Aagaard K, Morison J.  2005.  Dissolved oxygen extrema in the Arctic Ocean halocline from the North Pole to the Lincoln Sea. Deep-Sea Research Part I-Oceanographic Research Papers. 52:1138-1154.   10.1016/j.dsr.2005.01.007   AbstractWebsite

Dissolved oxygen (02) profiling by new generation sensors was conducted in the Arctic Ocean via aircraft during May 2003 as part of the North Pole Environmental Observatory (NPEO) and Freshwater Switchyard (SWYD) projects. At stations extending from the North Pole to the shelf off Ellesmere Island, such profiles display what appear to be various 02 maxima (with concentrations 70% of saturation or less) over depths of 70-110 m in the halocline, corresponding to salinity and temperature ranges of 33.3-33.9 and -1.7 to -1.5 degrees C. The features appear to be widely distributed: Similar features based on bottle data were recently reported for a subset of the 1997-1998 SHEBA stations in the southern Canada Basin and in recent Beaufort Sea sensor profiles. Oxygen sensor data from August 2002 Chukchi Borderlands (CBC) and 1994 Arctic Ocean Section (AOS) projects suggest that such features arise from interleaving of shelf-derived, O(2)-depleted waters. This generates apparent oxygen maxima in Arctic Basin profiles that would otherwise trend more smoothly from near-saturation at the surface to lower concentrations at depth. For example, in the Eurasian Basin, relatively low O(2) concentrations are observed at salinities of about 34.2 and 34.7. The less saline variant is identified as part of the lower halocline, a layer originally identified by a Eurasian Basin minimum in "NO," which, in the Canadian Basin, is reinforced by additional inputs. The more saline and thus denser variant appears to arise from transformations of Atlantic source waters over the Barents and/or Kara shelves. Additional low-oxygen waters are generated in the vicinity of the Chukchi Borderlands, from Pacific shelf water outflows that interleave with Eurasian waters that flow over the Lomonosov Ridge into the Makarov Basin and then into the Canada Basin. One such input is associated with the well-known silicate maximum that historically has been associated with a salinity of approximate to 33.1. Above that (32 < S < 33), there is a layer moderately elevated in temperature (summer Bering Sea water) that we show is also O(2)-depleted. We propose that these low O(2) waters influence the NPEO and SWYD profiles to varying extents in a manner reflective of the large-scale circulation. The patterns of halocline circulation we infer from the intrusive features defy a simple boundary-following cyclonic flow. These results demonstrate the value of the improved resolution made feasible with continuous O(2) Profiling. In the drive to better understand variability and change in the Arctic Ocean, deployment of appropriately calibrated CTD-O(2) packages offers the promise of important new insights into circulation and ecosystem function. (c) 2005 Elsevier Ltd. All rights reserved.

1989
Anderson, LG, Jones EP, Koltermann KP, Schlosser P, Swift JH, Wallace DWR.  1989.  The first oceanographic section across the Nansen Basin in the Arctic Ocean. Deep-Sea Research. 36:475-482.   10.1016/0198-0149(89)90048-4   AbstractWebsite

The first quasi-synoptic oceanographic section across a major deep basin of the Arctic Ocean reveals three different regimes: a narrow boundary current system along the northern Barents Shelf slope, a wide interior basin regime and a northern boundary current regime with several distinct cores along the Nansen-Gakkel Ridge at 86 degree N. The southern boundary current cores are marked by high oxygen concentrations, high salinities and low temperatures that indicate sources on the shelf and in Fram Strait. The northern boundary current regime contains water mass signatures that are thought to come from the Amundsen Basin as well as from Fram Strait. The Nansen Basin interior is only slowly ventilated from the boundary currents and shelves, the deep water having an age of several decades.