Summary: | These data were collected as part of the physical oceanographic component of the Chukchi Sea Offshore Monitoring in Drilling Area (COMIDA) Hanna Shoal Ecosystem Study. Hanna Shoal is a topographic feature in the northeastern Chukchi Sea that is both shallow (as little as 20m deep) and biologically productive. The earlier COMIDA: Chemistry and Benthos (CAB) study identified it as an area at which to focus additional ecological monitoring. To define the circulation around the Shoal, Acoustic Doppler Current Profilers (ADCPs) were deployed on six moorings on its northwest and northeast slopes on the 40, 50, and 60 m isobaths. These were initially deployed in August 2012 from the USCG Healy. They were then recovered and re-deployed in September 2013 from the Norseman II under the direction of Chief Scientist Peter Winsor (UAF). The same vessel and Chief Scientist conducted the recoveries in September 2014. Each mooring included a MicroCat temperature/conductivity/pressure (CTD) recorder mounted about 3 m above bottom. Two moorings, HS-NE_50m and HS-NE_60m in 2012-13, additionally included an ISCAT (upper level temperature-salinity-pressure sensors in a trawl resistant housing designed to survive impact by ice keels) at ~25 and 30 m depth, respectively. Circulation around Hanna Shoal was unknown, even though the area is biologically important. Moorings were placed on the northwest and northeast slope in order to detect the clockwise flow around the Shoal predicted by model results. The ISCAT and MicroCat pairs on these moorings were designed to measure changes in water column stratification.
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