High-Bandwidth Moorings with Profilers and Platforms
Cabled Moorings with Profilers and Platforms at the Cascadia Margin and Slope, and at Axial Seamount
The RSN Deep Profiler (DP) system is designed to collect oceanographic data profiles in water depths of up to 3000m. The DP system includes a modified McLane Mooring Profiler (MMP) vehicle that uses a motor traction drive to profile from near the sea surface to the seafloor along a tensioned mooring cable with a subsurface float. The system's dock assembly near the seafloor includes an inductive battery-charging dock for the vehicle battery, an inductive communication system that provides communications during profiling, and a Wi-fi antenna that provides high-speed communications while in the charging dock. The dock electronics will connect to the RSN power and fiber-optic data network using ROV-mateable underwater connectors. (Illustration by Nick Michel-Hart, University of Washington)
This winched shallow profiler science pod with be hosted on the 200-m platform of the RSN two-legged high-bandwidth mooring. The science pod will include numerous chemical and biological sensors, including pH, CO2, and nitrate. The profiler will make several trips through the water column each day, transmitting all data in real-time to the Internet. The two-way communication provided by the Primary Cable will allow adjusments of profiles in response to events of interest and characterization of thin layers. (Illustration by Patrick Waite, University of Washington)
The UW Regional Scale Nodes team is designing, fabricating, testing, and implementing state-of-the-art paired moorings that will be cabled to the Primary Infrastructure and will provide real- and near-real time data to the global community over the Internet. In total, six of these new moorings will be installed in 2014, spanning water depths from 2900m to 600m at three different sites: PN1A- Slope Base; PN1C - Offshore (shared with the Endurance Array); and PN3A - Base of Axial Seamount. Each mooring profiler and platform will be powered by the cable and will have bandwidth (Gbs) capabilities that allow for a broad suite of sensors. These sensors include real-time digital imaging and acquisition of high-bandwidth sonar and hydrophone data for biological applications. In concert, these instrumented platforms will provide unparalleled spatial-temporal resolution on biogeochemical processes, ocean acidification, and other oceanographic processes operative off the Oregon-Washington coast.
The two types of cabled moorings include the following:
1) A Deep Profiler hosting an instrumented deep wire crawler (McLane) that measures ocean properties from ~3000 m to ~ 200 m water depth. Power and data transfer will be provided to the Deep Profiler via an inductive couple. An extension cable running from a Low Power Junction Box will provide 375v power and 1GBs communications to the following instruments:
- CTD, Dissolved Oxygen, 3-D Single Point Current Meter -Temperature, and Fluorometers (CDOM, Chlorophyll-a, Optical Backscatter)
2) A two-legged mooring with a 200-m Platform (12 feet across) and an instrumented winched Shallow Profiler that travels from 200 m to just below the ocean's surface. Power (375 v) and communications (1Gbs) will be provided to this two-legged mooring via a Low Voltage Node. A science module (pod) on the 200-m platform, as well as the instrument pod on the winched profiler, can be installed/recovered using a robotic vehicle. This means that the entire mooring does not have to be recovered each year, thus lowering operations and maintenance costs. The same is true for the Deep Profiler.
The 200-m Platform instruments include the following:
- pH, Broadband Hydrophone, Fluorometer, CTD, Dissolved Oxygen, 5-beam ADCP, Digital Still Camera, and a150-kHz ADCP
The Shallow Profiler instruments include the following:
- CTD, Dissolved Oxygen, Nitrate, pH, Optical Attenuation, Spectral Irradiance, Photosynthetically Available Radiation, Fluorometer - 3 wavelengths, and a Current Meter
In addition, a cabled Seafloor Instrument Array associated with the moorings will document near-bottom and water-column processes. The Array's instruments will receive power and communications through a Medium Power Junction Box. Instruments include the following:
- 150-kHz ADCP, Broadband Hydrophone, Acoustic Modem, Optical Attenuation, CTD, Dissolved Oxygen, and a HPIES (Horizontal Electric Field, Pressure and Inverted Echo Sounder).
Shallow Profiler Platform
This platform at 200 m beneath the ocean's surface is on the RSN two-legged mooring. The 12-foot-across platform will host the instrumented Shallow Winched Profiler, as well as an instrument science module on the platform itself (including a digital still camera and ADCP). All data will be streamed in real-time through the seafloor cable and onto the Internet for ingestion and redistribution by the OOI Cyberinfrastructure. (Illustration by Patrick Waite, University of Washington).
Ocean conditions surrounding the OOI RSN are bracketed on the pelagic, or open-ocean, end by the OOI global site at Ocean Station Papa, and on the coastal end by the OOI Endurance Array. The OOI RSN resides in a complex system of currents, where wind- and tide-forced motions lead to turbulent mixing that aids transport of chemical and biological species. The Pacific Northwest is one of the most biologically productive regions of the world where hypoxia, ocean acidification, and harmful algal blooms are observed with increasing frequency. These complex physical, biological, and chemical processes are all intertwined and respond to forcing on a wide range of spatial and temporal scales. The cabled moored profilers at the base of the Cascadia Margin (Slope Base), in shallower waters along the Oregon margin west of Newport (Endurance Array), and at the base of Axial Seamount are well suited to resolve these water-column processes, as well as ocean-system responses to changing forcing conditions that result from climate change.