Surface-piercing profilers with acoustic Doppler current profilers (ADCPs) at their base (left) will be at the inshore and central sites of the Pioneer Array. Moored wire-following profilers with ADCPs (right) will be at the intermediate sites along the inshore/offshore line, and at the Array's upstream corners. (Jack Cook, Woods Hole Oceanographic Institution)
Coastal Surface-Piercing Profiler
The surface-piercing profiler mooring will be used at the coastal observatories -- the Pioneer Array in the Atlantic and the Endurance Array in the Pacific.
At the Pioneer Array, the mooring will support sensors in the profiling body and will have a frame mounted upward looking acoustic Doppler current profiler (ADCP). The frame will include a primary battery bank and power controller to re-charge the profiling package. The ADCP will be self powered and will include an inductive link. The profiler seats in the bottom frame when at the bottom of its travel, allowing onboard batteries to be recharged and data from the ADCP to be uploaded via an inductive link.
Endurance Oregon Line inshore mooring and the Washington Line shelf and inshore moorings will use a stand-alone profiler; Oregon Line the shelf and offshore moorings will be connected to the Regional Scale Node (RSN). The stand-alone profiler is internally powered and will communicate via Iridium telemetry while at the sea surface. The profiler can also communicate acoustically with the surface mooring located less than 2 km away. The profiler moorings connected to the RSN will receive power and communicate via the secondary cabled infrastructure. The shelf and offshore profilers will retain the capability to communicate acoustically with nearby surface moorings.
The Oregon Line surface-piercing profilers consist of an aluminum bottom frame that is approximately 1.7 m diameter and 1.4 m high, with mounting points for an ADCP and other near bottom sensors, anchor weight, an anchor release mechanism, and a profiling package that includes flotation material, a winch system, a sealed lead acid battery pack (12 Ah at 18-42 volts), controller, scientific sensors, and a radio and Iridium satellite telemetry system. The profiler package will extend 2 m or less above the top of the base. The connection between the bottom frame and profiling package is a synthetic line approximately 8 mm in diameter. When the profiling package is at the bottom of its travel it seats in the bottom frame and can communicate with and download data via an inductive link. These profiler systems can operate in depths approaching 200 meters depending on current conditions.
Coastal Wire-Following Profiler
The wire-following profiler mooring will be used in the coastal observatories -- the Pioneer Array in the Atlantic and at the offshore site for the Endurance Array's Washington Line in the Pacific. The mooring will support sensors in the profiling body and will have a frame mounted, upward looking acoustic Doppler current profiler (ADCP). The Pioneer wire-following profiler will be of conventional design from the anchor to the subsurface flotation sphere, but will also include a surface expression.
An electromechanical (EM) stretch mooring hose will connect a small surface buoy to the subsurface flotation sphere, providing compliance in the upper 15-20 m of the mooring (to accommodate tidal excursions and wave motion) while allowing the flotation sphere to maintain vertical tension in the wire-rope portion of the mooring on which the profiler rides.
The wire-following profiler will translate all but the upper 15 m of the water column and will be equipped with an ADCP situated near the bottom. Both will transmit data using inductive modems over the jacketed steel cable with seawater return, through conductors in the flotation sphere and stretch hose, to a receiver in the surface buoy.
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