News from Ocean Observatory Initiative
A new era of oceanography
In August, members of the OOI team aboard the R/V Neil Armstrong for the eighth turn of the Global Irminger Sea Array and members of OSNAP(Overturning in the Subpolar North Atlantic Program) onshore will work together to make near-real time shipboard CTD data available here. The OOI shipboard team will be working directly with an onshore expert hydrographer, Leah McRaven (PO WHOI), from the US OSNAP team to support collection of an optimized hydrographic data product. This collaboration will provide support for the OOI team through the cruise planning stages, during the cruise, and during initial data processing stages. In the end, both teams aim to document the process of collecting thoroughly vetted data from the shipboard CTD (conductivity, temperature, depth) system. A special feature of this collaboration will be the near real-time sharing of OOI shipboard CTD data with the public. Interested parties will have access to the same CTD profiles that McRaven will be reviewing. Additionally, McRaven will share brief reports online while the cruise is underway. The hydrographic data collection facilitated by OOI on the Irminger Sea cruise will bolster not only OOI end users, but also supports international oceanographic research projects, including OSNAP, AMOC (Atlantic Meridional Overturning Circulation) and BGC-ARGO(BioGeoChemical Array for Real-time Geostrophic Oceanography). “We hope sharing this data will present an opportunity for OOI end users to learn more about working with oceanographic data as well as good data practices,” said McRaven. Al Plueddemann, PI of OOI’s Coastal and Global Scale nodes, which includes the Global Irminger Array, added “This is a great example of a cross-project collaboration that expands the visibility of OOI data over the short-term and improves its quality for integration into long-term research projects like OSNAP.”
The Ocean Observatories Initiative Facility Board (OOIFB) provides independent input and guidance regarding the management and operation of the National Science Foundation-funded Ocean Observatories Initiative (OOI). The OOIFB works to expand scientific and public awareness of the OOI, and ensure that the oceanographic community is kept informed of developments of the OOI. The OOIFB is soliciting applications to fill one open membership position. The appointment will fill the remainder of an unexpired term and will be effective starting in September 2021 and run through June 2023. The selected individual will be eligible to serve a second term of 3-years. The OOIFB holds at least one in-person meeting per year and one web conference each month. Scientists with experience using scientific observing systems, such as the OOI, are encouraged to apply. In an effort to maintain the expertise and disciplinary depth on the committee, we are particularly interested in applicants with research experience using data from the OOI Global Arrays. However, all interested applicants will be considered. The responsibilities of the OOIFB may include, but are not limited to, the following:
- Serving as the prime scientific and technical conduit between the oceanographic community and NSF regarding OOI.
- Examining the accomplishments and work flow of the OOI Operator, in order to provide feedback regarding the OOI Annual Work Plans (AWPs).
- Via workshops, community meetings, and/or other mechanisms, stimulate and engage the user community in order to keep the accomplishments of the OOI at the cutting edge of scientific inquiry and technological innovation.
- Developing and implementing strategies to expand scientific and public awareness of the unique scientific and technological opportunities of the OOI.
A very engaged group of participants spent the week of June 21st thinking about how to optimize the Pioneer Array for its relocation to the southern Mid-Atlantic Bight (MAB) in 2024. The five-day Innovations Lab, sponsored by the National Science Foundation (NSF) was led by the OOIFB (Ocean Observatories Initiative Facilities Board), a talented team of “Sparks”, Knowinnovation, Inc. (KI), and expertly supported by the OOI Facility. The group identified a range of representative interdisciplinary science questions that can be addressed using the Pioneer Array within the MAB and proposed optimum locations and potential configurations for the array. Science question topics included air-sea interactions; the influence of estuarine plumes and the Gulf Stream on cross-shelf and shelf-slope exchanges and their impacts on ocean chemistry and biology; benthic-pelagic coupling; and canyon processes. Participants converged on a general region (see boxes in Figure 1 below) that would best address the science questions. [media-caption path="https://oceanobservatories.org/wp-content/uploads/2021/06/Google-earth-map.png" link="#"]Figure 1. Southern MAB Pioneer Array regions. The red box indicates the region where moorings would be located and the larger green box indicates the region where mobile assets (gliders and AUVs) would operate.[/media-caption] “The Innovations Lab was very successful, and we really appreciate the community sharing their innovative ideas with us in this essential first step,” said Kendra Daly, chair of the OOIFB. “The Innovations Lab provides an excellent start to a long process of fleshing out the details to ensure that the array provides data to investigate a broad range of interdisciplinary science questions, while also being robust enough to weather the challenging environmental conditions in the Mid-Atlantic Bight.” The OOIFB will continue to engage with the OOI community to refine the array’s design for implementation over the next two years. The Innovations Lab showed that there is strong community interest in coastal science, the potential for new partnerships, and excitement about implementing the Pioneer Array in its new location.
After 20 months in the water, the Global Station Papa Array will be turned (old moorings recovered and new ones deployed) in July for the eighth time. Normally, this array is turned every year, but last year the trip was cancelled due to constraints imposed by the COVID-19 pandemic. In early July, the OOI team will head to Seward, Alaska to begin preparations for this long-due operation. The OOI team will arrive in Seward and load the R/V Sikuliaqwith over 54 tons of equipment. Following one week of equipment mobilization and build, and a precautionary seven-day COVID isolation period, the team will depart for a 16-day cruise in the Northeast Pacific. The team will recover three Station Papa subsurface moorings and deploy three new ones. Along the way, they will also deploy two Open Ocean Gliders, recover one Profiling Glider, and conduct 11 CTD casts, which will help calibrate and validate the instruments on the array. The design of the moorings and gliders, as well as their planned locations, can be found here. The robust array was designed for a 12-month deployment between turns, but due to COVID this interval had to be extended to 20 months. The extended duration may have affected data quality since bio-fouling on instruments accumulates over time. However, past experience with extended durations has been positive such that the team’s expectations regarding data quality is high. “Regular maintenance is vital for keeping the arrays working and collecting data, so this cruise is an especially important one,” said Chief Scientist Kris Newhall, who leads the seven members of the Station Papa 8 team. The moorings have several design updates, including improved controllers and new positioning beacons with GPS and flashers built into the housing. The upgrades will increase the performance of the moorings and simplify recovery operations. The Global Station Papa Array is an important part of the OOI network, and the data it has collected is helping to shed light on the physical and biological dynamics for this region of the North Pacific.
As part of the ongoing the Ocean Observatories Initiative (OOI) effort to improve data quality, OOI is implementing Quality Assurance of Real-Time Oceanographic Data (QARTOD) tests on an instrument-by-instrument basis. Led by the United States Integrated Ocean Observing System (U.S. IOOS), the QARTOD effort draws on the ocean observing community to provide manuals, which outline and identify tests to evaluate data quality by variable and instrument type. Currently, OOI is focused on implementing the Gross Range and Climatology Tests for the variables associated with CTD, pH, and pCO2 sensors. Over the coming months tests will be applied to data collected by pressure sensors, bio-optical sensors, and dissolved oxygen sensors. Ultimately, where and when appropriate, QARTOD tests will be applied to the relevant variables for all OOI sensors. The Gross Range test aims to identify data that fall outside either the sensor measurement range or is a statistical outlier. OOI identifies failed/bad data with a threshold value based on the calibration range for a given sensor. We also calculate suspicious/interesting data thresholds as the mean ± 3 standard deviations based on the historical OOI data for the variable at a deployed location. As implemented by OOI, the Gross Range test identifies data that either fall outside of the sensor calibration range, and is thus “bad”, or data that are statistical outliers based on the historic OOI data for that location. The Climatology Test is a variation on the Gross Range Test, modifying the relevant suspicious/interesting data thresholds for each calendar-month by accounting for seasonal cycles. The OOI time series are short (<8 years) relative to the World Meteorological Organization (WMO) recommended 30-year climatology reference period. To help ensure quality, we calculate seasonal cycles for a given variable using harmonic analysis, a method that is less susceptible to spurious values that can arise either from data gaps, measurement errors or from the presence of real, but anomalous, geophysical conditions in the available record. First, we group the data by calendar-month (e.g. January, February, …, December) and calculate the average for each month. Then, we apply the monthly-averaged-data with a two-cycle (annual plus semiannual) harmonic model. Each harmonic is determined using a least-squares fit – a procedure that minimizes the sum of the squares of the differences between the data points and the curve to be fit. This produces a “climatological” fit for each calendar-month. Next, we calculate the standard deviation for each calendar-month from the grouped observations for the month. The thresholds for suspicious/interesting data are set as the climatological-fit ± 3 standard deviations. Occasionally, data gaps may mean that there are no historical observations for a given calendar-month. In these instances, we linearly interpolate the threshold from the nearest months. For sensors mounted on profiler moorings or vehicles, we first divide the data into subsets using standardized depth bins to account for differences in seasonality and variability at different depths in the water column. The resulting test identifies data that fall outside of typical seasonal variability determined from the historic OOI data for that location.