Posts Tagged ‘Endurance Array’
A Bountiful Sea of Data: Making Echosounder Data More Useful
[media-caption path="https://oceanobservatories.org/wp-content/uploads/2021/03/Screen-Shot-2021-03-30-at-5.51.41-PM.png" link="#"]Researchers used echosounder data from the Oregon Offshore site of the Coastal Endurance Array to develop a new methodology that makes it easier to extract dominant patterns and trends.[/media-caption]The ocean is like a underwater cocktail party. Imagine, as a researcher, trying to follow a story someone is telling while other loud conversations are in the background of a recording. This phenomenon, known as the “Cocktail Party Problem,” has been studied since the 1950s (Cherry, 1953; McDermott, 2009). Oceanographers face this challenge in sorting through ocean acoustics data, with its mixture of echoes from acoustic signals sent out to probe the ocean.
Oceanographer Wu-Jung Lee and data scientist Valentina Staneva, at the University of Washington, teamed up to tackle the challenge in a multidisciplinary approach to analyze the vast amounts of data generated by echosounders on Ocean Observatories Initiative (OOI) arrays. Their findings were published in The Journal of the Acoustical Society of America, where they proposed a new methodology that uses machine learning to parse out noisy outliers from rich echosounder datasets and to summarize large volumes of data in a compact and efficient way.
This new methodology will help researchers use data from long time series and extract dominant patterns and trends in sonar echoes to allow for better interpretation of what is happening in the water column.
The ocean is highly dynamic and complex at the Oregon Offshore site of the OOI Coastal Endurance Array, where echosounder data from a cabled sonar were used in this paper. At this site, zooplankton migrate on a diurnal basis from a few hundred meters to the surface, wind-stress curl and offshore eddies interact with the coastal circulation, and a subsurface undercurrent moves poleward. The echosounder data offer opportunities to better understand the animals’ response to immediate environmental conditions and long-term trends. During the total eclipse of the Sun in August 2017, for example, echosounders captured the zooplankton’s reaction to the suddenly dimmed sunlight by moving upwards as if it was dusk time for them to swim toward the surface to feed (Barth et al, 2018).
Open access of echosounder datasets from the OOI arrays offers researchers the potential to study trends that occur over extended stretches of time or space. But commonly these rich datasets are underused because they require significant processing to parse out what is important from what is not.
Echosounders work by sending out pulses of sound waves that bounce off objects. Based on how long it takes for the reflected echo to come back to the sensor, researchers can determine the distance of the object. That data can be visualized as an echogram, an image similar to an ultrasound image of an unborn baby.
But unlike an ultrasound of a baby, when an undersea acoustic sensor records a signal, it may be a combination of signals from different sources. For example, the signal might be echoes bouncing off zooplankton or schools of fish.
[caption id="attachment_20566" align="alignleft" width="350"]
(A) Data used in this work were collected by a three-frequency echosounder installed on a Regional Cabled Array Shallow Profiler mooring hosting an underwater platform (200 m water depth) and profiler science pod located at the Oregon Offshore site of the OOI Coastal Endurance Array (red triangle). The symbols indicate the locations of all OOI echosounders installed along the coast of Oregon and Washington. (B) The transducers are integrated into the mooring platform (from left to right: 120, 200, and 38 kHz). The platform also hosts an instrumented profiler that traverses the water column above the echosounder from ~ 200 m to ~ 5m beneath the ocean’s surface. (Image credit: UW/NSF-OOI/WHOI-V15).[/caption]
“When the scatterers are of different size, they will reflect the sound at different frequencies with different strengths,” said Lee. “So, by looking at how strong an echo is at different frequencies, you will get an idea of the range of sizes that you are seeing in your echogram.”
Current echogram analysis commonly requires human judgement and physics-based models to separate the sources and obtain useful summary statistics. But for large volumes of data that span months or even years, that analysis can be too much for a person or small group of researchers to handle. Lee and Staneva’s new methodology utilizes machine learning algorithms to do this inspection automatically.
“Instead of having millions of pixels that you don’t know how to interpret, machine learning reduces the dataset to a few patterns that are easier to analyze,” said Staneva.
Machine learning ensures that the analysis will be data-driven and standardized, thus reducing the human bias and replicability challenges inherently present in manual approaches.
“That’s the really powerful part of this type of methodology,” said Lee. “To be able to go from the data-driven direction and say, what can we learn from this dataset if we do not know what may have happened in a particular location or time period.”
Lee and Staneva hope that by making the echosounder data and analytical methods open access, it will improve the democratization of data and make it more usable for everybody, even those who do not live by the ocean.
In the future, they plan to continue working together and use their new methodology to analyze the over 1000 days of echosounder data from the OOI Endurance Coastal and Regional Cabled Array region.
References
Lee, W-J and Staneva, V (2021).Compact representation of temporal processes in echosounder time series via matrix decomposition. Special Issue on Machine Learning in Acoustics. The Journal of the Acoustical Society of America.
Barth JA, Fram JP, et al. (2018). Warm Blobs, Low-Oxygen Events, and an Eclipse: The Ocean Observatories Initiative Endurance Array Captures Them All.Oceanography, Vol 31.
McDermott, J (2009). The Cocktail Party Problem.Current Biology, Vol 19, Issue 22.
Cherry EC (1953). Some Experiments on the Recognition of Speech, with One and Two Ears.The Journal of the Acoustical Society of America. Vol. 25, No.5.
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Spring Expeditions: Keeping OOI Arrays Fully Operational
OOI teams were in the water on opposite coasts in late March to service the Pioneer and Endurance Arrays. The teams will “turn” the moorings (recover old and deploy new) to keep the arrays continually collecting and reporting data back to shore. This is the 14th turn of the Endurance Array; the 16th for the Pioneer Array.
The Endurance 14 Team set sail from Newport Oregon aboard the R/V Sikuliaq on 24 March for a 15-day expedition. The Pioneer 16 Team departed from Woods Hole, MA, a few days later on 29 March aboard the R/V Armstrong for a 21-day mission. Both expeditions will require two legs because of the need to transport a huge amount of equipment. The equipment for the Pioneer Array weighs more than 129 tons. The Endurance equipment tops the scale at 95 tons.
Departures for both teams occurred after arranging for reduced occupancy on site and social distancing during preparation, followed by 14 days of quarantine to meet COVID-19 restrictions. And while onboard, COVID has necessitated other changes ranging from smaller science parties to scheduled meal times to allow for social distancing.
“It is very impressive that the OOI team has been able to continue to service these arrays in spite of the challenges presented by COVID,” said Al Plueddemann, Chief Scientist of the Pioneer 16 Expedition. “The ocean is a tough environment in which to keep equipment operational, even in normal times. This year, in particular, has required both our shore-based staff and those onboard to be adaptable, flexible, and innovative to get the job done.”
[media-caption path="https://oceanobservatories.org/wp-content/uploads/2021/03/burnin_Travis.jpg" link="#"]The full cycle of preparation for an OOI mooring service cruise takes many months. The “burn-in” period for Pioneer-16, during which equipment is assembled and tested, began in January 2021 with snow on the ground outside of the LOSOS building on the WHOI campus. Credit:Rebecca Travis © WHOI.[/media-caption]In addition to the mooring and deployment recoveries, both teams are deploying and recovering gliders that collect additional data within the water column and the area between the moorings. They also are conducting CTD casts and water sampling at the mooring sites, and doing meteorological comparisons between ship and buoys. The Pioneer Team will be operating autonomous underwater vehicles (AUVs), while the Endurance Team will have its inaugural use of OOI’s own remotely operated vehicle (ROV) to recover anchors at the Oregon shelf site.
“In normal times, we would invite external students and scientists along to conduct ancillary experiments on the cruise,” said Edward Dever, Chief Scientist for Endurance 14. “But given the limited science party allowed onboard due to COVID-19, the OOI team will be conducting some of this additional work to ensure the continuity of these experiments.”
For Endurance 14, this work includes collection of organisms that grow on panels attached to Endurance buoys for invasive species research, collection of settling organisms on devices attached to Multi-Function Nodes, which power near bottom data instruments, and test deployments of tagged fish acoustic monitors on near surface instrument frames on three moorings.
Likewise, the Pioneer 16 Team is helping ensure ongoing science investigations installing and operating unattended underway sampling for the Northeast U.S. Shelf Long-Term Ecological Research (LTER) project and conducting CTD casts at LTER sites during the cruise. They will also conduct communication tests at the Offshore mooring site in support of the Keck-funded 3-D Acoustic Telescope project.
Science teams of 9-10 people on each cruise are sharing the multitude of tasks needed for the moored array service.
[media-caption path="https://oceanobservatories.org/wp-content/uploads//2021/03/Screen-Shot-2021-04-01-at-9.19.20-AM.png" link="#"]OOI’s remotely operated vehicle will be used for the first-time during Endurance 14. Credit: Seaview Systems.[/media-caption]
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Women Who Make OOI Happen
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Keeping OOI operational and providing data around the clock requires a whole team of people working behind the scenes. Because March is Women’s History Month, we have taken the opportunity to ask a few women to share their stories about coming to and working for OOI. By featuring women who contribute to OOI’s success, we honor those women, past and present, who have made OOI possible.
Diana Wickman
Senior Engineering Assistant II
Diana’s job involves the operation, maintenance and piloting of OOI’s fleet of Slocum Gliders and two REMUS 600 AUVs. She is based at Wood Hole Oceanographic Institution.
How did you end up at OOI? When people ask me this question I often say “by accident.” I interviewed with OOI 11 years ago in early 2009 when the program was just kicking off. I had a degree in Marine Science from the University of Connecticut and was wrapping up a four-year stint in the US Air Force as a Satellite Communications Technician – an odd combo to say the least. I applied to be an electrical engineering technician but was instead offered the job of Configuration Manager. I had spent about three years doing configuration management when the program acquired its first Slocum Gliders. I remember walking past the gliders in the hallway one day, so shiny and yellow, and I was immediately hooked. I wanted to know all about these giant “tub toys.” The rest is history.
What is the most challenging part of your job? The most matter-of-fact answer to this question is: keeping the ocean OUT of the inside of the robot, but that is only half of the challenge. The ocean, especially the areas OOI operates in, is really good at breaking things. The OOI Gliders are designed to be deployed with no hands-on human interaction for up to one year at a time. When I’m in the lab working on the gliders I cannot stop at “it is working today,” I need to constantly be thinking “will this remain working for up to a year?” It has been very challenging and also rewarding to learn a system well enough to be able to predict future failures and prevent them before they arise.
What do you enjoy most about your job? I’m only part joking when I tell people the robots are like my kids. They seem to have their own unique “personalities”; some are difficult and some are easy, some seem to love to be deployed and others seem to want to sit in the lab, some are warriors and others wave the white flag at the first sign of trouble. For me, the most rewarding part of the job is seeing the gliders succeed at their missions and come home after their long deployments. Finally getting them on the bench in the lab after a year apart is kind of surreal. I love the story each glider tells of its deployment through the engineering data it gathered at sea. In laying my hands on the vehicle again I become a detective of sorts: did the Glider have a run in with a shark, a near miss with a leak, a collision with an ice berg?
Anything else you’d like to add? Having gone from the Air Force where my particular job was 96% male dominated, to ocean engineering which is also heavily male dominated (although there are many, many brilliant female engineers and engineering technicians at WHOI to look up to), I have no idea what it’s like to work in a non-male dominated career field. Being a woman in a very heavily male dominated career field has its challenges. There have been times I have been the only woman in a meeting, or on a vessel during a cruise (and often in those cases have been the one in charge). I have experienced people make assumptions about my role on the team, or my ability to do my job due to my gender. Luckily for me I’m loud, largely oblivious, and occasionally overconfident, which has helped me break through some of those gender assumptions that may have held other women back. For these traits I both thank and blame my paternal Grandmother.
Trina Litchendorf
Oceanographer IV
Trina is part of the OOI instrument team at the University of Washington’s Applied Physics Laboratory, where they test, maintain and deploy all the commercially-produced instrumentation on the Regional Cabled Array.
What does your job entail?
There are over two dozen different types of oceanographic instruments deployed on the Regional Cabled Array – from A to Z – ADCPs (acoustic Doppler current profilers) to zooplankton sonars, and everything in between: CO2 and pH sensors, CTDs, digital still cameras, fluorometers, hydrophones, oxygen optodes, seismometers, and velocity sensors, to name a few. Every summer I go to sea off the Oregon and Washington Coast with the Woods Hole Oceanographic Institution’s Jason remotely operated vehicle (ROV) team. The ROV team recovers all of the instrument platforms that were deployed the previous year and then deploys and connects new instrument platforms. After the cruise, in the fall, we send all of the instruments recovered during the cruise, about 135 of them, to their manufacturers so the instruments can be refurbished and calibrated. The instruments start coming back from servicing in the late fall and throughout the winter. During that time, I thoroughly test the instruments to ensure they are working perfectly before they are mounted on their deployment platforms in the spring. Then they go through a round of integration testing on the platforms before the cruise. All of this careful testing ensures high-quality data and a low failure rate once the instruments are deployed. Come summer, I am back out at sea, ready to repeat the yearly maintenance cycle.
How did you end up in this job? I started working at the Applied Physics Lab as a full-time employee in 2001. The projects I have worked on since then have involved everything from lasers, gas chromatographs, and infra-red imagers to underwater vehicles, such as Seagliders and REMUS AUVs (autonomous underwater vehicles). I also have been to sea numerous times for those projects. My familiarity with various oceanographic equipment and my sea-going experience made for a natural fit for the RCA Instrument Team, which I joined in 2015.
What is the most challenging part of your position? The cruises are the most challenging. They average about 40 days, give or take, and the work is non- stop. ROV operations happen around the clock and there is always a lot to do to get the instrument platforms ready to be deployed for the next dive. Every instrument must be powered on for one final check, the platforms must be rigged properly for the ROV, and every instrument on the platform must be photographed before we send it over the side. I also run some of the dives, sitting to the left of the ROV pilot in the control van and telling him or her the order of operations and which cables to plug in. These dives can sometimes last 12 hours or more and I usually pull a few all-nighters. During cruises, we have to come into port several times to offload all the recovered gear and load the next set of equipment, which we try to accomplish in a day or two. The cruises are like marathons and require a lot of stamina. It is also hard to be away from friends and family for so long, especially during the summer when Seattle has its best weather and I’m wearing a down jacket and wool cap because it’s so overcast and cold offshore.
What do you enjoy most about your job? The cruises. As challenging as they are, the cruises also offer the greatest rewards. I enjoy working with the undergraduate students who go to sea with us for their first oceanographic cruises; their enthusiasm reminds me of my first time at sea. There are beautiful sunrises and sunsets to see, the full moon shining on the ocean is stunning, and on moonless nights, the Milky Way is visible and the stars are spectacular. Whales and dolphins occasionally swim by, and there are incredible things to see on the seafloor with the ROV’s HD (high-definition) cameras. My favorite part of the cruise every year is when we do photo-surveys of the hydrothermal vent fields and the lava flows at Axial Caldera. Seeing the interesting biology that lives at these depths and the unique lava and vent formations never gets old!
Anything else you’d like to add? In the early 2000’s, when I was an oceanography undergrad at the University of Washington, my Geological Oceanography course was taught by Drs. Deb Kelly and John Delaney. One day, Dr. Delaney gave a presentation to our class and described a revolutionary way the oceans would be studied in the future: with regional scale ocean observatories that could send data, in real time, over the Internet to scientists around the world. This was years before the Canadian NEPTUNE array, the world’s first such underwater observatory, had been deployed. I remember thinking what a fascinating idea that was. It’s amazing now to be a part of it all, going to sea alongside Dr. Kelly, and deploying the instruments that I tested on the array. I look forward to the future and a day when Dr. Delaney’s other vision is a reality: resident AUVs stationed year-round on the Regional Cabled Array, ready to be deployed immediately after an event such as an eruption at Axial Seamount.
Meghan Donohue
Senior Engineering Assistant I Meghan’s job is ever-evolving. She recently changed from being a mooring tech at Wood Hole Oceanographic Institution, who served as the deck lead on multiple OOI cruises, to being a full-time OOI tech, who preps and builds the moorings for the cruises. Her new position allows her to play more with the computer side of things rather than focusing solely on mechanical issues.
How did you end up at OOI? I was a hyper-focused child who knew from a very young age that I wanted to be an oceanographer. Everything I did, from going on my first real research cruise in high school on the R/V Connecticut to studying Marine Science Physics at the University of San Diego to getting my mariners license at the Maine Maritime Academy, eventually landed me here. I worked for Scripps Institution of Oceanography as a shipboard tech, running the deck. I planned all the cruises, operated all of the oceanographic equipment and managed the computer systems on their smaller vessels. At Scripps, I met John Kemp, head of the WHOI mooring group, which eventually led to a job offer. The majority of the work I did for the WHOI mooring group was with OOI.
What is the most challenging part of your job? Balancing family and work has been my greatest challenge. Trying to rebalance that is part of the reason why I chose to change positions.
What do you enjoy most about your job? I like being able to teach the new techs and crew how to do the moorings. And I enjoy splicing—the act of weaving a piece of line together. It’s just relaxing. In addition to splicing line on the global moorings, I also splice the lines used for the Pioneer ARMS and profiler linepacks. I have made all of the ARMS linepacks with various helpers for the Pioneer cruises since the fall of 2014.
Kristin Politano
Faculty Research Assistant Kristin works with a team at Oregon State University on instrument quality control, refurbishment, and data monitoring. She also manages mooring integration for the Endurance Array, which involves building and integrating the electrical components of the moorings with the instrumentation.
How did you end up at OOI? In 2016, I joined the Oregon State University branch of PISCO (Partnership for the Interdisciplinary Studies of Coastal Oceans) as their lead mooring technician. That position allowed me to gain valuable experience with the process of building, integrating, deploying, and maintaining mooring systems. I participated in several OOI cruises while I was at PISCO and was able to meet the team of people who build and maintain the Endurance Array. When they eventually had an opening for a new position, I jumped at the chance to work with them full time.
What is the most challenging part of your job? Every new deployment brings its own set of challenges, but most of the big ones are time-related. We work closely with vendors and suppliers to stick to a timeline during builds, but it’s inevitable that delays in servicing or deliveries occur. When that happens, you have to be ready to move quickly when the parts eventually show up. Another big challenge is the lack of time to make significant improvements to the moorings. There are moments when we’re building the systems that we think “wouldn’t it be smarter it if we did it like this…” or “we could really make this more reliable if we changed that…” and often times the schedule doesn’t allow us the flexibility to make those changes.
What do you enjoy most about your job? I really enjoy problem solving, and in a lot of ways, the moorings are just like big puzzles. All the parts and pieces have to fit together perfectly for the system to function properly. Building the moorings in our shop and running them through integration and burn-in testing allows us to chase down and solve any issues that could mean the difference between a successful deployment, and a mooring that’s at sea for months with failed components. I like being able isolate and solve issues when they arise.
Jennifer Batryn
Engineer II
Jennifer works with (almost) all of the more than 1200 instruments that pass through the OOI program at WHOI. She is involved in the whole life cycle of the instruments, including testing, configuring, troubleshooting, deploying, data monitoring, and refurbishment.
How did you end up at OOI? I received my degree in mechanical engineering, thinking that I would end up in some sort of aeronautics or robotics field. I had never really considered a career centered around the ocean until taking part in a research program through my university. Through that program, we traveled to Malta for a month and collaborated with local archeologists, using small ROVs (remotely operated vehicles) and an AUV (autonomous underwater vehicle) to map out wells, cisterns, an underwater cave, and other features of interest around the island. Being able to work with interesting technology, travel and do field work, and collaborate with a multidisciplinary group really appealed to me, and I was sold on ocean research after that. I got involved with any ocean-based work I could afterwards, including internships at UC San Diego, National Geographic, and a summer fellowship at Woods Hole Oceanographic Institution. After college, I was thrilled to find my way back to WHOI, where I joined the OOI team.
What is the most challenging part of your position? Schedules and lack of time are the most challenging parts. Depending on how our cruise schedule line up for a particular year, it can be a surprisingly tight turnaround between recovering a set of moorings and when we need to make everything ready to deploy again. Inevitably, we have sensors and other components that come back from sea damaged. We then run into schedule conflicts with vendors and suppliers, and later discover instrument communication or sampling issues during our burn-in/testing period that need troubleshooting. The ship is going to sail regardless, which leaves very limited flexibility with timing, and sometimes there’s a real crunch period leading up to a deployment. It can also be very challenging to ensure we get good data for the entire duration of any particular deployment. The ocean is a tough environment for electronics and sensors, especially when in the water for prolonged periods. We run into problems with biofouling, physical damage from severe storms, icing, waves, or vibrations, and limitations of battery life, reagent, and other consumables.
What do you enjoy most about your job? Going to sea to support deployments and recoveries of our moorings is a nice change of pace from working in the lab and is very rewarding (if not exhausting). It’s great to see all of the work building up and burning-in of the mooring to that final end product of deployment in the ocean for six months to a year. It’s also great seeing all the data successfully come through back to shore. Long, tiring days at sea are offset by seeing all the wildlife and other natural sights in the open ocean (starry nights with no light pollution, Northern lights, stormy seas, icebergs, etc.), and traveling to different ports and experiencing different parts of the world. My dog (Teddy) was actually a Chilean street dog that I met while down in Punta Arenas preparing a mooring before a cruise. I ended up falling in love and bringing him back home with me after the cruise. Hard to beat that! It also has been really rewarding to see more people actually using OOI data, knowing that the work we are putting in is going towards the creation of a really unique, long-term data set.
Anything else you’d like to add? Going to school in such a male dominated field, it has been neat to find a core group of really smart and talented women within OOI. Everyone comes from such diverse backgrounds, and yet we all found our way to this project. Naturally the whole team is great though. It is equal parts entertaining and inspiring to work alongside everyone on our team, whether in the lab, on deck deploying a mooring, or scraping barnacles after a recovery.
Photo Credits from top
Diana Wickman headshot and glider Photo: Diana Wickman©WHOI for both
Trina Litchendorf securing oceanographic instruments on the Science Pod platform prior to a cruise. Photo: Dana Manalang
Meghan Donohue Photo: ©WHOI
Kristin Politano Photo: OSU
Jennifer Batryn in the freezer of the R/V Armstrong working on instrument calibrations at a controlled (cold) temp during the Pioneer 16 operation and maintenance cruise. Photo: Rebecca Travis©WHOI
Read MoreEndurance Oregon Shelf Data Provides Insights into Bottom Boundary Layer Oxygen Fluxes
Adapted and condensed by OOI from Reimers et al., 2021, doi:/10.1029/2020JC016828
In February 2021 JGR Oceans article, Clare E. Reimers (Oregon State University) and Kristen Fogaren (Boston College) used data from the Endurance Array Oregon Shelf to advance understanding of how the benthic boundary layer on the Oregon Shelf in winter depends on surface-wave mixing and interactions with the seafloor.
The oceanic bottom boundary layer (BBL) is the portion of the water column close to the seafloor where water motions and properties are influenced significantly by the seabed. This study examines conditions in the BBL in winter on the Oregon shelf. Dynamic rates of sediment oxygen consumption (explicitly oxygen fluxes) are derived from high-frequency, near-seafloor measurements made at water depths of 30 and 80 m. The strong back-and-forth motions of waves, which in winter form sand ripples, pump oxygen into surface sediments, and contribute to the generation of turbulence in the BBL, were found to have primed the seabed for higher oxygen uptake rates than observed previously, in summer. Since oxygen is used primarily in biological reactions that also consume organic matter, the winter rates of oxygen utilization indicate that sources of organic matter are retained in, or introduced to, the BBL throughout the year. These findings counter former descriptions of this ecosystem as one where organic matter is largely transported off the shelf during winter. This new understanding highlights the importance of adding variable rates of local seafloor oxygen consumption and organic carbon retention, with circulation and stratification conditions, into model predictions of the seasonal cycle of oxygen.
The rest of the article can be accessed here.
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Low Dissolved Oxygen off Washington and Oregon Coast Impacted by Upwelling in 2017
In the summer of 2020, the Rutgers University Ocean Data Labs project worked with the Rutgers Research Internships in Ocean Science to support ten undergraduate students in a virtual Research Experiences for Undergraduates program. Rutgers led two weeks of research methods training and Python coding instruction. This was followed by six weeks of independent study with one of 13 research mentors.
Dr. Tom Connolly (Moss Landing Marine Labs, San Jose State University) advised Andrea Selkow from Austin College, Texas on her study of dissolved oxygen (DO) off the Washington and Oregon coasts using the OOI Endurance Array.
Selkow evaluated DO data from Endurance Array Surface Moorings during 2017 and 2018. She presented this work as a poster at the conclusion of her summer REU. Selkow focused on the question: Are there similarities in the dissolved oxygen concentrations off the coast of Oregon and Washington during a known low oxygen event? She also considered why there might exist differences based on the spatial variability of wind stress forcing, i.e., do the strong Oregon winds cause dissolved oxygen concentrations to be lower at the Oregon mooring compared to the Washington moorings. Finally, she reviewed the data and tried to answer whether the oxygen data were accurate or affected by biofouling.
She used datasets from the OR and WA Inshore Shelf Mooring time-series and WA Shelf Mooring time-series from Endurance Array. Her focus was on the seafloor data because that is where the lowest oxygen concentrations were expected to be observed.
Selkow focused her attention on low DO observed in the summer of 2017. While Barth et al. (2018) presented a report on these data for one event in July 2017, she expanded the analysis to include the Washington shelf and inshore moorings. She plotted time series data and used cruise data to validate these time series. While overall seasonal trends in DO were similar, she found dissolved oxygen is routinely more quickly depleted off the coast of Oregon than Washington during a low oxygen event (Figure 25). She also looked at the cross-shelf variability in DO time series and found dissolved oxygen is more quickly depleted at the shelf mooring than at the inshore shelf mooring. Upwelling is known to drive the low oxygen events and she inferred that the weaker southward winds over the Washington shelf may be why DO decreases at a slower rate off Washington than Oregon.
References
Barth, J.A., J.P. Fram, E.P. Dever, C.M. Risien, C.E. Wingard, R.W. Collier, and T.D. Kearney. 2018. Warm blobs, low-oxygen events, and an eclipse: The Ocean Observatories Initiative Endurance Array captures them all. Oceanography 31(1):90–97,
Selkow, A. and T. Connelly. Low Dissolved Oxygen off Washington and Oregon Coast Impacted by Upwelling in 2017, Accessed 13 Jan 2021.
Read MoreDelineating Biochemical Processes in the Northern California Upwelling System
Excerpted from the OOI Quarterly Report, 2022.
[media-caption path="/wp-content/uploads/2020/10/Endurance-Array-Science-Highlight.png" link="#"]Figure 19: Regional T/S variability at the Washington offshore profiling mooring. The end member Pacific Subarctic Upper Water (PSUW) and Pacific Equatorial Water (PEW) masses are indicated on each plot at the left and right respectively. T/S at the mooring is a mixture of PSUW and PEW. The left plot shows the seasonal variability. The right plot shows interannual variability in summer. Interannual variability from 100-250m exceeds seasonal variability. In 2015, T/S at the mooring is closer in character to climatological averages at Vancouver Island, BC while in 2018, T/S at the mooring is similar to that south of Newport, OR. Figure from Risien et al. adapted from Thomson and Krassovski (2010).[/media-caption]
Risien et al. (2020) presented over five years of observations from the OOI Washington offshore profiling mooring. First deployed in 2014, the Washington offshore profiler mooring is on the continental slope about 65 km west of Westport, WA. Its wire Following Profiler samples the water column from 30 m depth down to 500 m, ascending and descending three to four times per day. Traveling at approximately 25 cm/s, the profiler carries physical (temperature, salinity, pressure, and velocity) and biochemical (photosynthetically active radiation, chlorophyll, colored dissolved organic matter fluorescence, optical backscatter, and dissolved oxygen) sensors. The data presented included more than 12,000 profiles. These data were processed using a newly developed Matlab toolbox.
The observations resolve biochemical processes such as carbon export and dissolved oxygen variability in the deep source waters of the Northern California Upwelling System. Within the Northern California Current System, over the slope there is a large-scale north-south variation in temperature and salinity (T/S). Regional T/S variability can be understood as a mixing between warmer, more saline Pacific Equatorial Water (PEW) to the south, and fresher, colder Pacific Subarctic Upper Water (PSUW) to the north. Preliminary results show significant interannual variability of T/S water properties between 100-250 meters. In summer, interannual T/S variability is larger than the mean seasonal cycle (see Fig 19). While summer T/S variability is greatest on the interannual scale, T/S does covary on a seasonal scale with dissolved Oxygen (DO), spiciness and Particulate Organic Carbon (POC). In particular, warmer, more saline water is associated with lower DO in fall and winter.
Risien, C.M., R.A. Desiderio, L.W. Juranek, and J.P. Fram (2020), Sustained, High-Resolution Profiler Observations from the Washington Continental Slope , Abstract [IS43A-05] presented at Ocean Sciences Meeting 2020, San Diego, CA, 17-21 Feb.
Thomson, R. E., and Krassovski, M. V. (2010), Poleward reach of the California Undercurrent extension, J. Geophys. Res., 115, C09027, doi:10.1029/2010JC006280.
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UNOLS Extends Guidance to Suspend Cruises through 1 July 2020
The University-National Oceanographic Laboratory System (UNOLS), which coordinates oceanographic ships’ schedules, recommended on 17 March 2020 that cruise activities be paused for 30 days due to the COVID-19 pandemic. On 30 March UNOLS extended its guidance to suspend research cruises to July 1 2020. This action is designed to protect the health and safety of the crews and scientific parties.
The planned spring operation and maintenance (O&M) cruise to the Endurance Array in March was affected by the original 30-day guidance. The upcoming O&M cruises for the Pioneer, Irminger, and Papa Arrays aboard R/V Neil Armstrong and R/V Sikuliaq are impacted by this latest guidance.
The OOI is working with UNOLS and ship operators to find potential opportunities to complete the scheduled cruises and conduct needed maintenance on the arrays. In the meantime, there’s been no interruption in OOI data. OOI data continue to be collected and made available for use by the scientific and educational communities.
Read MoreFifteen Findings in 15 minutes
“Just like lightning,” in one-minute presentations, 15 scientists shared amazing ways they are using OOI data in scientific investigations and in the classroom. This round of lightning talks capped the Ocean Observatories Initiative Facility Board’s (OOIFB) Town Hall at the 2020 Ocean Sciences Meeting on 20 February, demonstrating the multiple and creative ways OOI data are being used to answer key science questions in a changing environment.
The presentations ranged from how students are using real-life and real-time OOI data to advance their understanding of scientific principles to how researchers are using OOI data to identify the presence of marine life by sound to how modelers are making OOI data more accessible and useable.
“We were simply thrilled by the depth, breadth, and range of applications of OOI data shown during this lightning round,” Kendra Daly, chair of the OOIFB. “We were pleased so many presenters were willing to accept the challenge. This enthusiastic response clearly shows that OOI data are being used to help answer important science questions.”
Brief summaries of the talks are presented below.
Advancing science
Isabela Le Bras, Scripps Institution of Oceanography, reported on a recent article in Geophysical Research Letters, where she and her colleagues describe how they used data from the Irminger Sea Array moorings (2014–2016) to identify two water masses formed by convection and showing that they have different rates of export in the western boundary current. Upper Irminger Sea Intermediate Water appears to form near the boundary current and is exported rapidly within three months of its formation. Deep Irminger Sea Intermediate Water forms in the basin interior and is exported on longer time scales. The subduction of these waters into the boundary current is consistent with an eddy transport mechanism. The eddy transport process is more effective for the waters cooled near the boundary current, implying that cooling near boundary currents may be more important for the climate than has been appreciated to date.
Since 2017, Clare Reimers and Kristen Fogaren, Oregon State University, have been working to assess seasonal variability in benthic oxygen consumption and the contribution of benthic respiration to the development of hypoxic conditions in the northern California Current, using time series data from the OOI Endurance Array. Reimers and Fogaren measured benthic oxygen consumption rates using in situ eddy covariation techniques and ex situ core incubations, during a series of ten cruises that allowed sampling near the Endurance Oregon Shelf and Inshore stations, in all seasons. During these cruises, the researchers used real-time data provided by the Endurance Array to optimize the settings for their eddy covariance deployments. They are now examining property-relationships in discrete bottom water samples collected during the cruises and using data from OOI assets to help separate influences of mixing and biochemical processes in the water column and sediments. The researchers are also synthesizing benthic flux measurements and placing these rates in the context of cross-shelf glider measurements and benthic node time series.
Adrienne Silver, University of Massachusetts Dartmouth provided details about how she is using Pioneer Array data to learn more about the influence of warm core rings on Shelf break circulation. Results from a 40-year Warm Core Ring census show a regime shift in warm core ring formation at 2000, with the number of rings doubling from an average of 18 rings per year (during 1980-1999) to 33 rings per year (during 2000-2019). This regime shift creates a large increase in the amount of warm salty water being transported northward toward the shelf from the Gulf Stream. The preferred pathway of these rings, or the Ring Corridor seem to indicate their proximity to the shelf break and the Pioneer array during their lifetime. The goal of Silver’s project is to understand how these warm core rings affect the shelf break exchange while traveling along the shelf. A large focus of the study will be on the salinity intrusion events which might be sourced from these warm core rings.
Liz Ferguson, CEO and founder of Ocean Science Analytics, is using data from OOI’s Coastal Endurance and Regional Cabled Arrays to determine the variables that are most useful for assessing the ecosystem of this region and obtaining baseline information on marine mammal acoustic presence for use in monitoring. Using long term physical and biological data provided by these arrays, Ferguson is assessing long-standing shifts in the ecology of this coastal and offshore environment by associating physical oceanographic variables with the vocal presence of marine mammals using the broadband hydrophone data. Temporal changes in the occurrence of marine mammal species such as killer whales, sperm whales and dolphins can be used as an indicator of ecosystem shifts over time. She is analyzing passive acoustic data provided by the OOI arrays to determine the presence of vocally active marine mammal species, identify their spatial and temporal use of these sites, and combining this information with the physical oceanographic variables to assess the ecological characteristics associated with marine mammal occurrence.
Sam Urmy of the Monterey Bay Aquarium Research Institute (MBARI) also is using OOI acoustical data in his research. Using an upward-looking echosounder and a high-frequency hydrophone at MBARI’s Monterey Accelerated Research System, Urmy showed how small animals in the epipelagic and mesopelagic altered their behavior in response to predators. These responses included abrupt dives during bouts of foraging by dolphins, changes in depth to avoid predatory fish schools, and dramatic alterations to daily vertical migratory behavior. Continual observations of the mesopelagic with active and passive acoustics are revealing several dynamic predator-prey interactions in an ecosystem that is typically thought of as relatively slow and static.
Veronica Tamsitt of the University of New South Wales used the OOI’s Southern Ocean mooring and the Southern Ocean Flux Site (SOFS, in the Southeast Indian) to study the Sub Antarctic Mode water (SAMW) formation. Tamsitt’s and her colleagues findings were reported in the Journal of Climate in March 2020. Using data from the two mooring locations, the researchers were able to compare and contrast characteristics and variability of air-sea heat fluxes, mixed-layer depths, and SAMW formation. The researchers found that inter mixed-layer depth anomalies tended to be intermittent at the two moorings, where anomalously deep mixed layers were associated with anomalous advection of cold air from the south, and conversely shallow mixed layers correspond to warm air from the north. Both the winter heat flux and mixed-layer depth anomalies, however, showed a complex spatial pattern, with both positive and negative anomalies in both the Indian and Pacific basins that Tasmitt and colleagues relate to the leading modes of climate variability in the Southern Ocean.
Editor’s note: The Southern Ocean Array was decommissioned in January 2020. Its data, however, are still available for use by researchers, students, and the public.
Bringing OOI data into the classroom
Sage Lichtenwalner, Department of Marine and Coastal Sciences at Rutgers, The State University of New Jersey reported on the progress of the Ocean Data Labs Project. This project is a Rutgers-led effort to build a “Community of Practice” to tap into the firehose of OOI ocean data to support undergraduate education. To date, the project has hosted four “development” workshops that introduced participants to the OOI, conducted data processing with Python notebooks, and shared effective teaching strategies, in addition to a series of introductory workshops and webinars. As part of the development workshops, 56 university, college, and community college faculty designed 19 new “Data Explorations,” featuring web-based interactive “widgets” that allow students to interact with pre-selected data from the OOI. The project also sponsors a series of webinars, a fellowship program, and is compiling a library of resources (including coding notebooks, datasets, and case studies in teaching) to help the community.
Cheryl Greengrove, University of Washington Tacoma, summarized an article in the March issue of Oceanography that she and colleagues from across the United States wrote detailing ways to integrate OOI data into the undergraduate curriculum. The wealth of freely-accessible data provided by OOI platforms, many of which can be viewed in real or near-real time, provides an opportunity to bring these authentic data into undergraduate classrooms. The TOS article highlights existing educational resources derived from OOI data that are ready for other educators to incorporate into their own classrooms, as well as presents opportunities for new resources to be developed by the community. Examples of undergraduate introductory oceanography OOI data-based lessons using existing interactive online data widgets with curated OOI data on primary productivity, salinity, and tectonics and seamounts are presented, as well as ways to use OOI data to engage students in undergraduate research. The authors provide a synthesis of existing tools and resources as a practical how-to guide to support new resource development and invite other educators to develop and implement new educational resources based on OOI data.
Matthew Iacchei, Hawaiʻi Pacific University, presented how he has been integrating OOI data explorations to supplement his upper division oceanography lecture and labs with real data from around the world. Last semester, he had students explore patterns of dissolved oxygen and impacts of anoxia at the coastal endurance array in Oregon and compare that data to dissolved oxygen data the students collected in Kāneʻohe Bay, Hawaiʻi. This semester, students are working through two exercises with OOI data as part of their primary productivity lab (perfect, as it is now online!). Students will compare vertical profiles from Hawaiʻi with seasonal variations across the world, and will compare latitudinal drivers of primary production using data from a time-series from the Southern Ocean Array.
Strengthening OOI data usability
Wu-Jung Lee, a senior oceanographer at the Applied Physics Laboratory, University of Washington, is using data collected by the OOI to develop new methodologies for analyzing long-term ocean sonar time series. In a project funded by the National Science Foundation, she and her colleagues show that unsupervised matrix decomposition techniques are effective in discovering dominant patterns from large volumes of data, which can be used to describe changes in the sonar observation. Their preliminary analysis also show that the summaries provided by these methods facilitate direct comparison and interpretation with other ocean environmental parameters concurrently recorded by the OOI. A parallel effort that spun out of this project is an open-source software package echopype, which was created to enable interoperable and scalable processing of biological information from ocean sonar data.
As part of the Rutgers Ocean Modeling Group, in conjunction with University of California Santa Cruz, John Wilkin and Elias Hunter are delivering a high-resolution data assimilative ocean model analysis of the environs of the Pioneer Coastal Array, including a systematic evaluation of the information content of different elements of the observing network. The project uses the Regional Ocean Modeling System with 4-Dimensional Variational data assimilation. To produce a comprehensive multi-year (2014-2018) analysis required them to assimilate all available Pioneer CTD data, with quality checks, in a rolling sequence of data assimilation analysis intervals. They used three days of data in each analysis, which required queries to with a time range constraint and relevant platform (i.e. glider, profiler, fixed sensor), migrating all Pioneer CTD data (wire following profilers, gliders, fixed sensors, plus ADCP velocity) to an ERDDAP server. The simple graphing capabilities in ERDDAP allow quick browsing of the data to trace quality control or availability issues, and ERDDAP provides a robust back-end to other web services to create more sophisticated graphical views, or time series analysis. Using the ERDDAP Slide Sorter tool, they operate a quick look Control Panel to monitor the data availability and quality.
Mitchell Scott and colleagues Aaron Marburg and Bhuvan Malladihalli Shashidhara at the University of Washington, are studying how to segment macrofauna from the background environment using OOI data from the Regional Cabled Axial Seamount Array. Their long-term goal is to use an automated approach to study species variation over time, and against other environmental factors. Their initial step focuses specifically on scale worms, which are very camouflaged, making them difficult to detect. To address this, the researchers initially used a deep learning model, called U-Net, to detect and localize the scale worm locations within an image. To address the high rate of false positives using this model, they added an additional classifier (a VGG-16 model) to verify the presence of scaleworms. This combined, applied approach proved feasible for scale worm detection and localization. Yet because the environment of the Axial Seamount is so dynamic due to the growth and decay of chimneys at the site and resulting changes in bacteria and macrofauna present, they found the performance of the model decreased over time.
Weifeng (Gordon) Zhang of Woods Hole Oceanographic Institution has been using Pioneer Array data to understand the physical processes occurring at the Mid-Atlantic Bight shelf break, including the intrusion of Gulf Stream warm-core ring water onto the shelf and the ring-induced subduction of the biologically productive shelf water into the slope sea. His findings were reported in a Geophysical Research Letters paper where data from the Pioneer Array moorings and gliders demonstrated the anomalous intrusion of the warm and salty ring water onto the shelf and revealed the subsurface structure of the intrusion. Zhang also shared findings reported in the Journal of Geophysical Research: Oceans where data from the Pioneer Array showed a distinct pattern of relatively cold and fresh shelf water going underneath the intruding ring water. These results show the subduction of the shelf water into the slope sea and a pathway of shelf water exiting the shelf. In both instances, Zhang and his colleagues used computer modeling to study the dynamics of these water masses. These two studies together suggest that shelf break processes are complex and require more studies in the region.
Hilary Palevsky of Boston College presented results from an ongoing project funded by the National Science Foundation’s Chemical Oceanography program, using biogeochemical data from the OOI Irminger Sea Array. Analysis of dissolved oxygen data on OOI Irminger Sea gliders and moorings from 2014-2016 showed the importance of biogeochemical data collected over the full seasonal cycle and throughout the entire water column, due to the influence of subsurface respiration and deep winter convection on biological carbon sequestration. The OOI Irminger Sea array is the first source of such full-depth year-round data in the subpolar North Atlantic. To quantitatively evaluate the annual rate of carbon sequestration by the biological pump and the role of deep winter convection, Palevsky and colleague David Nicholson of the Woods Hole Oceanographic Institution collaborated with OOI to improve the calibration of oxygen data at the Irminger Sea array by modifying the configuration of glider oxygen sensors to enable calibration in air each time the glider surfaces, which improves the accuracy and utility of the data collected both from gliders and from moorings. Palevsky presented preliminary results demonstrating successful glider air calibration at the Irminger array in 2018-2019 as well as work by student Lucy Wanzer, Wellesley College, demonstrating the importance of well-calibrated oxygen time series data to determine interannual variability in rates of subsurface respiration and deep winter ventilation in the Irminger Sea.
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Spring Endurance Cruise Canceled due to COVID-19
The spring 2020 OOI Endurance Operations and Management (O&M) turn cruise has been canceled due to travel and personnel restrictions imposed to stem the spread of the virus COVID-19. The 16-day cruise was set to depart on 31 March from Newport, Oregon aboard the R/V Sikuliaq to service the array off the Oregon and Washington coasts.
Jonathan Fram, Program Manager of the Endurance Array, explains in this EOS article some of the possible implications of the cancellation, which may range from some of the moorings losing power, to the gliders running out of batteries, to possibly missing the recording data documenting the coastal ocean’s transition from winter to spring.
The fall 2020 Endurance turn cruise (currently scheduled for September) is expected to take place.
Read MoreEndurance Cruise Delayed by COVID-19
The spring 2020 OOI Endurance Operations and Management (O&M) turn cruise has been delayed for at least 30 days due to travel and personnel restrictions imposed to stem the spread of the virus COVID-19.
The 16-day cruise was set to depart on 31 March from Newport, Oregon aboard the R/V Sikuliaq to service the array off the Oregon and Washington coasts. The R/V Sikuliaq is part of the US academic research fleet managed by UNOLS (the University-National Oceanographic Laboratory System). UNOLS imposed a 30-day suspension in fleet operations on 13 March to help ensure the safety of the ship’s crew and science party and to mitigate the risk of virus spread. Rescheduling of activities will commence once the situation stabilizes and UNOLS sees a path forward to re-start research vessel operations safely.
Upcoming O&M cruises for the Pioneer, Irminger, and Papa Arrays also are scheduled aboard UNOLS vessels (R/V Neil Armstrong and R/V Sikuliaq). These cruises fall outside of the UNOLS current 30-day suspension so cruise preparation continues.
We do not anticipate that cruise schedule changes will affect the collection nor dissemination of OOI data, which will continue to be available for users here.
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