Schematic of a global site.

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The planned Global Scale Nodes will provide comprehensive surface-to-seafloor observing capability. Paired surface and subsurface moorings will provide the capacity to resolve surface forcing, and water column, benthic, and seafloor processes in time and in the vertical. Flanking moorings and gliders will collect data on the site’s mesoscale context, including spatial gradients and advective influences. (Woods Hole Oceanographic Institution)

Schematic of a Global site, depicting the triangular array  formed by a surface/subsurface mooring pair (foreground) and two flanking moorings (background).

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Schematic of a Global site, depicting the triangular array  formed by a surface/subsurface mooring pair (foreground) and two flanking moorings (background). (Woods Hole Oceanographic Institution)

Global Scale Nodes

The Global Scale Nodes consist of four Global Arrays located in the following critical, yet under-sampled, high-latitude locations

Each array will use a combination of horizontally fixed platforms (moorings) with moored profilers to address the requirement to sample the full water column and mobile platforms (AUVs and gliders) to provide simultaneous spatial and temporal sampling capabilities. These platforms deploy a multidisciplinary set of core sensors and also provide capacity (space, power, and bandwidth) for additional science user instrumentation. 

OOI infrastructure will provide the power, bandwidth, and platform space to support more capable sensor packages, bring back as much data in near real time as possible from these under-sampled regions, and permit two-way communications to control and change sampling strategies in response to contextual information.

Components

Each site will have a subsurface profiler mooring close to the surface mooring; that mooring will have two profilers. One will operate from ~200 m to the surface and the other from ~200 m to the seafloor. The upper profiler will penetrate the surface, allowing satellite data telemetry.

Two additional subsurface moorings will be deployed to form a triangular array ~50 km on a side. These flanking moorings have their uppermost flotation at ~30 m depth and instruments at discrete depths along the mooring line. They will provide data intermittently, using the gliders for data collection from the moorings. Moored sensors will sample physical, chemical, and biological variability.

Sampling within and around the triangular array will be done using several gliders. These gliders will carry multidisciplinary sensor suites will be commandable to alter their sampling patterns.

The Global site surface moorings will use an inverse catenary mooring line incorporating inductive and acoustic telemetry to subsurface instrumentation. The buoy will be designed to self-right and carry electronics and storage batteries. A combination of solar (deck-mounted) and wind (tower-mounted) power-generation systems will provide continuous power delivery capability. A mast will provide mounting for air-sea interaction sensors. This design can be launched, maintained, and recovered by University National Oceanographic Laboratory System (UNOLS) vessels.