Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Citing OOI Data

Refer to specific guidance related to citing OOI data on the OOI website at https://oceanobservatories.org/how-to-use-acknowledge-and-cite-data/. 

OOI Regional Cabled Array Sampling Guidelines

RCA includes 3 Shallow Profiler Moorings, 3 Deep Profiler Moorings, 2 Benthic Experiment Packages (BEP) and a host of seafloor instruments, along with primary nodes and junction boxes along the 900 km of high-power, high-bandwidth backbone fiber optic cables. Niskin bottles attached to the  Remotely Operated Vehicle (ROV) capture water samples near seafloor instruments. In general, water samples are collected for analysis at depths that correspond to instrumentation making in situ measurements at platforms and profilers.   A 24-bottle CTD rosette is allowed to equilibrate at target depths for at least 1 minute or more (depending on conditions) and a minimum of 30 seconds between duplicates.

Sampling at the RCA mooring locations entails the full suite of measurements (O2, Salts, Carbon, Nutrients, Chlorophyll). Sampling near the seafloor instruments vary depending on which sensors are present at the location.

Carbon System Measurements

Carbon system measurements were provided by the laboratory of Burke Hales at Oregon State University. All carbon parameters were reported at in situ temperatures. Calculated carbon parameters were generated by Hales using custom software routines and published values for the relevant carbon chemistry constants. The carbonic acid dissociation constants were from Millero (2010), with full-resolution constants provided by Millero via private communication and equal to Lueker’s constants at salinities greater than 25. Additional constants used in the calculations were Kw from Millero (1995), Kb from Dickson (1990), Ksp for calcite and aragonite from Mucci (1980), and Kh from Weiss (1973). Alkalinity was modeled as HCO3⁻ + 2CO3²⁻ + B(OH)4⁻ + OH⁻ − H⁺.

File/Row Representation of Water Samples

There should be one row for each station-cast-niskin bottle set. Multiple samples for the same parameter from a single niskin bottle are split into separate rows, with the associated CTD data copied to the new row. The first row of the file is the column headers.

Data Fill Values and Flag Description

The data flags are presented in the summary sheet as a 16-bit array, read from right-to-left, where a 1 in a particular bit position indicates a particular flag meaning applies. For example, a flag of 0000000000000010 for the column **CTD_File_Flag** indicates that the cast was a data cast only.

For full details about flag meanings, refer to the Readme files available for download in the Supplemental Files section of this metadata page. 

- Loaded 10 CSV files (Cabled-6_TN326_Discrete_Summary.csv, Cabled-8_RR1713-RR1717_Discrete_Summary.csv, Cabled-7_SKQ201610S_Discrete_Summary.csv, Cabled-9_RR1809-RR1812_Discrete_Summary.csv, Cabled-10_AT4212_Discrete_Summary.csv, Cabled-11_TN382_Discrete_Summary.csv, Cabled-12_TN393_Discrete_Summary.csv, Cabled-13_TN407_Discrete_Summary.csv, Cabled-14_TN422_Discrete_Summary.csv, Cabled-15_AT50-29_Discrete_Summary.csv) using filenames as table names; empty strings, "nd", and "-9999999" treated as missing values
- Concatenated all 10 tables into a single table named 1001459_v1_ooi_regional_cabled_array_discrete_water_sampling_data, mapping 80 columns by name; empty strings, "nd", and "-9999999" treated as missing values
- Renamed all 80 columns to use underscores in place of spaces and special characters (e.g., "Target Asset" to Target_Asset, "Start Latitude [degrees]" to Start_Latitude, "CTD Bottle Closure Time [UTC]" to CTD_Bottle_Closure_Time, "Discrete pH [Total scale]" to Discrete_pH, "Calculated Omega-A" to Calculated_Omega_A, etc.)
- Set data types for all columns: Start_Time and CTD_Bottle_Closure_Time as datetime (format %Y-%m-%dT%H:%M:%S.%fZ); numeric columns for CTD measurements, discrete sample measurements, and calculated carbonate system parameters; integer types for Calculated_DIC, Calculated_pCO2, Discrete_Alkalinity, Discrete_pH, Discrete_pH_Replicate_Flag, pH_Analysis_Temp; string types for flag columns, Cast, Cruise, Station, Target_Asset, CTD_File, and Niskin_Bottle_Position
- Applied BCO-DMO metadata (standard_name_id, supplied_units, description, and is_primary flags) to all 80 columns; CTD_Depth and CTD_Latitude designated as primary parameters
- Output written to 1001459_v1_ooi_regional_cabled_array_discrete_water_sampling_data.csv

The hydrographic sampling performed by the Ocean Observatories Initiative (OOI) as part of each research array turn represents a significant collection of valuable physical, chemical, and biological information. The collected hydrographic data include oxygen, salinity, nutrient (nitrate, nitrite, silicate, phosphate, ammonium), chlorophyll, and carbon system (dissolved inorganic carbon, total alkalinity, pH and partial pressure of CO₂) measurements. These data serve several important functions. First, they are necessary for the validation and evaluation of the moored instrumentation at each Array. Furthermore, the annual (Global Arrays and the Regional Cabled Array (RCA) or biannual (Coastal Arrays and the Endurance Array) collection of data at the same locations provides a unique timeseries of a large set of water properties following established community standards and methods, independent of its association with the OOI instrumentation.

The Ocean Observatories Initiative (OOI) is a science-driven ocean observing network that delivers real-time data to address critical science questions regarding the world's oceans. Funded by the National Science Foundation to encourage scientific investigation, OOI data are freely available online to anyone with an Internet connection. OOI was designed as a long-term project to collect ocean data for up to 30 years. This longevity makes it possible to measure and directly observe both short-lived episodic events and longer-term changes occurring in the ocean. Such data make it possible to better understand ocean processes and how the ocean is changing.

The OOI has five active research arrays that comprise the three major observatory elements linked together by instrument, infrastructure, and information management systems. Global Ocean Arrays consist of moored arrays and autonomous vehicles that provide time-series observations and mesoscale spatial sampling at sparsely sampled, high-latitude regions critical to our understanding of climate, the carbon cycle, and ocean circulation. The Regional Cabled Array consists of fiber-optic cables off the Oregon coast that provide unprecedented power, bandwidth, and communication to seafloor instrumentation and profiler moorings, enabling monitoring of volcanic and hydrothermal activity, methane seeps, earthquakes, and myriad ocean processes in coastal and blue water environments. Coastal Arrays consist of cross-shelf moored arrays and autonomous vehicles that observe the dynamic coastal environment, enabling examination of upwelling, shelf break fronts, and cross-shelf exchanges.

These marine arrays are outfitted with more than 900 instruments — of 45 different types — measuring more than 200 different parameters. These instruments gather physical, chemical, geological, and biological data – from the air-sea interface to the seafloor. The data collected are transmitted through a cyberinfrastructure, an information management system that allows users to access real- to near real-time data from suites of sensors. The OOI provides annotations and automated quality control for data streams and is working to meet the IOOS Quality Assurance of Real Time Ocean Data (QARTOD) standards.