Posts Tagged ‘gliders’

UGA Skidaway Institute receives funding for regional glider network

July 1, 2016

University of Georgia Skidaway Institute of Oceanography researcher Catherine Edwards is leading a team that has received a five-year, $750,000 grant from the Southeast Coastal Ocean Observing Regional Association, or SECOORA, to establish a regional glider network.

Also known as autonomous underwater vehicles, the gliders are torpedo-shaped crafts that can be packed with sensors and sent on underwater missions to collect oceanographic data. Equipped with satellite phones, the gliders surface periodically to transmit their recorded data and to receive new instructions during missions that can last from weeks to months.

UGA Skidaway Institute of Oceanography researcher Catherine Edwards assembles the tail cone assembly of a glider.

UGA Skidaway Institute of Oceanography researcher Catherine Edwards assembles the tail cone assembly of a glider.

The team will work collaboratively to operate regular glider missions on the continental shelf in an area from North Carolina to Florida known as the South Atlantic Bight. Regular coordinated experiments will involve simultaneous deployment of gliders at multiple locations off Florida, Georgia and North Carolina. Sensors on the gliders will allow the team to map temperature, salinity, density, dissolved oxygen and other scientific data over the entire South Atlantic Bight. The data will help scientists understand ocean processes and how the ocean physics may affect fisheries—for example, the location of fronts or areas of increased productivity where fish often congregate.

“This glider observatory is the first time regular glider efforts have been funded in the South Atlantic Bight and is complementary to larger SECOORA efforts in observing and modeling,” Edwards said. “The work is highly leveraged by contributions from each of the team members and partnerships with fisheries and observing groups at the National Oceanic and Atmospheric Administration and NASA.”

Edwards and her team have designed the deployments with input from fisheries management partners and interests of commercial and recreational fisheries. Gliders will also be outfitted with passive and active acoustics receivers that will record sound and measure signals from tagged fish.   Fisheries managers at Gray’s Reef National Marine Sanctuary, state Department of Natural Resources offices, the South Atlantic Fisheries Management Council and others will be able use this information to better understand the ocean “soundscape,” fish migrations and key species use of their habitat.

“The glider missions will contribute important information related to research underway at Gray’s Reef,” said Sarah Fangman, superintendent of Gray’s Reef National Marine Sanctuary. “We have been studying fish movement patterns inside the sanctuary, and the gliders’ acoustic receivers will provide a valuable new tool to expand where we can observe fish movements.”

In addition to regular coordinated experiments with multiple gliders and maximum regional coverage, the project will leverage opportunities to develop regular transects in areas where glider data may be of interest, for example near marine protected areas like Gray’s Reef National Marine Sanctuary and other critical habitat zones designated by the South Atlantic Fisheries Management Council.

The glider data will provide valuable information for validation of ocean models—regional models of ocean circulation funded by SECOORA as well as the larger modeling community. Further, the data will be packaged and used to improve ocean model forecasts.

“We’re sending all of the glider data to the National Glider Data Assembly Center as it comes in so that it can be assimilated into the U.S. Navy’s operational models,” Edwards said. “The gliders will improve Navy forecasts on the fly with real time data.”

The remainder of the research team includes Chad Lembke from the University of South Florida, Ruoying He from North Carolina State University, Harvey Seim from the University of North Carolina and Fumin Zhang from the Georgia Institute of Technology.

Data and maps from the project will be shared freely and made available to the research community, fisheries managers and other stakeholders and the general public in near-real time through SECOORA at http://secoora.org/ and the National Data Buoy Center.

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UGA Skidaway Institute scientists study dynamic Cape Hatteras waters

April 5, 2016

 

Sometimes called the “graveyard of the Atlantic” because of the large number of shipwrecks there, the waters off of Cape Hatteras on the North Carolina coast are some of the least understood on the U.S. eastern seaboard. University of Georgia Skidaway Institute of Oceanography scientist Dana Savidge is leading a team, which also includes UGA Skidaway Institute scientist Catherine Edwards, to investigate the dynamic forces that characterize those waters.

The four-year project, informally called PEACH: Processes driving Exchange at Cape Hatteras, is funded by $5 million grant from the National Science Foundation. Skidaway Institute will receive $1.2 million for its part.

UGA Skidaway Institute scientists Dana Savidge (l) and Catherine Edwards

UGA Skidaway Institute scientists Dana Savidge (l) and Catherine Edwards

Two opposing deep ocean currents collide at Cape Hatteras, making the Atlantic Ocean near there highly dynamic. The warm Gulf Stream hugs the edge of the continental shelf as it flows north from the tip of Florida.  At Cape Hatteras, it opposes a colder current, the Slope Sea Gyre current, that moves southward along the mid-Atlantic coast and breaks away from the coast toward northern Europe. As in the deep ocean, the cool shelf waters of the mid-Atlantic continental shelf meet the warm salty shelf waters from the south at Cape Hatteras.

The convergence of all of these currents at one place means that, after long lifetimes in the sunlit shallow shelves, these waters may export large quantities of organic carbon—small plants and animals that have grown up on the shelf—to the open ocean. Scientists have little understanding of the details of how that happens and how it is controlled by the high-energy winds, waves and interaction the between the constantly changing Gulf Stream and Slope Sea Gyre currents.Cape Hatteras Project Map 2 w

According to Savidge, the area is very difficult to observe because the water is shallow, the sea-state can be challenging and the convergence of strong currents at one place make it hard to capture features of interest.

“It’s difficult to get enough instruments in the water because conditions change rapidly over short distances, and it’s hard to keep them there because conditions are rough,” she said. “Ships work nicely for many of these measurements, but frequently, the ships get chased to shore because of bad weather.”

To overcome the limitations of ship-based work, the research team will use a combination of both shore- and ocean-based instruments to record the movement and characteristics of the streams of water. A system of high-frequency radar stations will monitor surface currents on the continental shelf all the way out to the shoreward edge of the Gulf Stream, providing real-time maps of surface currents.

“Measuring surface currents remotely with the radars is a real advantage here,” Savidge said. “They cover regions that are too shallow for mobile vehicles like ships to operate while providing detailed information over areas where circulation can change quite dramatically over short times and distances.”

Edwards will lead a robotic observational component in which pairs of autonomous underwater vehicles called gliders will patrol the shelf to the north and south of Cape Hatteras.  Packed with instruments to measure temperature, salinity, dissolved oxygen and bio-optical properties of the ocean, both shelf- and deep-water gliders fly untethered through the submarine environment, sending their data to shore at regular intervals via satellite.

To compensate for the notoriously difficult conditions, Edwards will take advantage of a novel glider navigation system she developed with students and collaborators at Georgia Tech that automatically adjusts the glider mission based on ocean forecasts as well as data collected in real time.

“Our experiments show that we can keep the gliders where they need to be to collect the data we need,” she said. “The best part is that we get to put the maps of surface currents together with the subsurface information from the gliders, and we can make all of this information available in real time to scientists, fishermen and the general public.”

The researchers will also place a number of moorings and upward-pointing echo sounders on the sea floor. These acoustic units will track the water movement while also recording temperature and density.  PEACH will focus primarily on the physics of the ocean, but the information the researchers gather will also help scientists more fully understand the chemistry and biology, and may cast light on issues like carbon cycling and global climate change.

“Everyone is interested in the global carbon budget, and the effect of the coastal seas on that budget is not well understood,” Savidge said. “For example, many scientists consider the continental shelf to be a sink for carbon, because there is a lot of biology going on and it draws in carbon.

“However, there are indications that the shelf south of Hatteras is both a sink and a source of carbon. This project may help clarify that picture.”

The project will run through March 2020. The remaining members of the research team are Harvey Seim and John Bane of the University of North Carolina; Ruoying He of North Carolina State University; and Robert Todd, Magdalena Andres and Glen Gawarkiewicz from Woods Hole Oceanographic Institute.

 

Scientists use underwater robots to excite students about science

December 4, 2014

Educators and scientists from the University of Georgia Skidaway Institute of Oceanography and the UGA Marine Extension Service have developed a novel education program based on ocean robots to spark an interest in science and mathematics in middle and high school students. The team invented a board game that lets students explore different strategies for navigating autonomous underwater vehicles, called AUVs or gliders, through the ocean.

The program, “Choose Your Own Adventure,” capitalizes on Skidaway Institute’s expertise with AUVs and MAREX’s extensive history of marine education. Skidaway Institute scientist and UGA faculty member Catherine Edwards and MAREX faculty members Mary Sweeney-Reeves and Mare Timmons are directing the one-year project, which demonstrates the decision-making process in “driving” gliders.

Gliders are untethered, torpedo-shaped vehicles that are launched into the ocean to collect data as they move through the water. They glide up and down by adjusting their buoyancy and pitch. Gliders can remain on a mission for weeks at a time, equipped with sensors and recorders to collect observations of temperature, salinity, dissolved oxygen, and other biological and physical conditions, even under the roughest weather. Every four to six hours over their mission, they surface and connect to servers on land to report their position and vehicle and mission information. They also can send data back to shore or receive new instructions from pilots anywhere in the world. Skidaway Institute’s glider, nicknamed “Modena,” has been used in several recent projects, including “Gliderpalooza,” a simultaneous, cooperative launch of dozens of AUVs from different institutions in 2013 and again in 2014.

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Skidaway Institute scientist Catherine Edwards and MAREX faculty member Mare Timmons (far right) cheer on a small child who tried her hand at the “Choose Your Own Adventure” game at Skidaway Marine Science Day on Oct. 25.

“Gliders are education-friendly, but the existing outreach activities are stale,” Edwards said. “We are developing the next generation of AUV outreach programs by combining cutting-edge, interdisciplinary research with educational activities and strong STEM components.”

The AUV activity/game is a part of an outreach program targeting mostly middle school students and it highlights the problem of working with the strong tides that are characteristic of the Georgia coast. A big issue in operating gliders is developing a guidance and navigation system that will function well in strong currents. The fast-moving Gulf Stream, located roughly 100 miles off the Georgia beaches, also introduces navigation problems.

“Although the AUVs have Global Positioning Systems and can be programmed to travel a set course, tidal and Gulf Stream currents can exceed the glider’s forward speed, which can take the instrument off course and keep us from collecting data where we need it,” Edwards said. “By estimating forecasts of these currents in advance, our software system can predict the best possible route for the glider to take, which helps collect the best possible data.”

On the education side, the predictability of tides makes the proposed program highly intuitive and education-friendly. The activity/game incorporates student role-playing as an AUV maneuvers through a playing field of vector currents on a game board. The student decides how many of his or her moves to spend fighting the current and how many to spend moving toward the finish line. Successful arrival at the destination depends on how the individual pilot responds to currents en route.

Activities depend on grade level, so middle school students have different objectives than those in high school. However, all the activities address the direction and speed the AUV travels to a destination. The AUV direction and speed will depend on the sea state, such as strong currents, storms or high winds.

Teachers April Meeks and Ben Wells from Oglethorpe Academy have offered their classes as a test-bed for the game. The two have worked closely with the team to integrate classroom concepts into the game and guide discussions about strategy based on the math. Since the activities are multidisciplinary, the teachers’ expertise in building a math curriculum has been valuable as the team integrates concepts of marine science, math and engineering into classroom activities. Rolling giant dice is a fun activity that attracts the students—everyone wants to roll the dice. So far, the feedback has been very positive.

“The students really seem to love it,” Sweeney-Reeves said. “More importantly, they are making the connection between the game and science, and learning.

“It took a period of time for some students to understand the concept but after starting the second round, they had the game/activity figured out. The excitement peaked at Oglethorpe Middle School when Mr. Wells played against the students and we really saw the competition heat up.”

Edwards added, “We knew we had a hit when we saw students jump up in celebration when the currents were favorable and pout when they were blown off course.”

The team demonstrated the game at the campus’s annual open house, Skidaway Marine Science Day, in late October, with a life-sized version of the board game with giant dice. Over 120 students played the game, racing against each other as they explored different strategies to win in three- to five-person heats. Sweeney-Reeves and Timmons also rolled out the game for educators at the Georgia Association of Marine Educators annual conference on Tybee Island earlier this month.

“The conference attendees were excited to use the giant dice to roll and hedge their bets on where they could navigate to the finish line,” Timmons said. “This is much like how the AUV is programmed to reach its sampling assignment in the ocean.”

Timmons said the teachers at the conference laughed as they saw the big game board spread out on the sidewalk. “Towards the end as teachers were close to the finish line they shouted, ‘right!’, mentally trying to encourage the roll of the die to their advantage.”

Timmons and Sweeney-Reeves think the game has real-life applications and hope the students can use the concepts they learn in the classroom for swimming in our own local waters. The next step is to expand the classroom demonstrations to Coastal Middle School in Chatham County and Richmond Hill Middle School.

The activities allow students to develop analytical skills in a program that will be compliant with Next Generation Science Standards for the 21st Century in the common core state curriculum.

“We hope this one-year program will serve as a springboard for future funding and continued joint outreach by Skidaway Institute and Marine Extension,” Edwards said. “We’d love to develop computer games and apps for tablets and mobile phones that let students fly gliders through even more realistic scenarios based on the measurements we collect in real time.”

The program is being funded through a joint grant from Skidaway Institute, UGA Office of Public Service and Outreach, and the UGA President’s Venture Fund. The UGA President’s Venture Fund is intended to assist with significant funding challenges or opportunities. The fund also supports small programs and projects in amounts typically ranging from $500 to $5,000.

The Skidaway Institute of Oceanography is a research unit of the University of Georgia located on Skidaway Island. Its mission is to provide a nationally and internationally recognized center of excellence in marine science through research and education. The UGA Marine Extension Service is a unit of the Office of Public Service and Outreach.

For additional information, contact Catherine Edwards at 912-598-2471 or catherine.edwards@skio.uga.edu; Mary Sweeney-Reeves at 912-598-2350 or msweeney@uga.edu; or Maryellen Timmons at 912-598-2353 or mare@uga.edu.

Skidaway Institute, Georgia Tech-Savannah partner on phytoplankton research

April 18, 2011

Sometimes scientific advances provide answers, and sometimes, they simply present more questions. That is what happened when scientists began using satellite imagery to study the ocean.

When Skidaway Institute of Oceanography scientists Jim Nelson and Catherine Edwards looked at satellite imagery of the ocean off the Carolinas, they noticed persistent blooms of phytoplankton, an important part of the marine food web. These mysterious blooms occurred during the winter along edge of the continental shelf off Long Bay — located between Cape Romain, South Carolina and Cape Fear, North Carolina. Phytoplankton blooms like those observed off Long Bay can provide a considerable boost to the bottom of the food chain, with significant implications for fisheries.

“The immediate cause of the blooms is an input of nutrients, like nitrogen and phosphorous, associated with transport and mixing of deep, cold onto the continental shelf,” said Edwards. “The Long Bay blooms persist for weeks or even months during the winter, suggesting multiple modes of nutrient input.”

Two of the guiding questions are why this feature is so persistent over the winter, and what are the dynamics that sustain this bloom?

Edwards and Nelson are teaming with Harvey Seim from the University of North Carolina and Fumin Zhang from Georgia Tech-Savannah on a project to answer those questions. The project is funded by a $1.6 million grant from the National Science Foundation supporting a team of scientists from all three institutions. With the help of Skidaway Institute research coordinators Trent Moore, Julie Amft and Charles Robertson, the project team will deploy moored and mobile instrument packages and conduct shipboard surveys to test hypotheses of how the winter blooms are formed and sustained.

The team will use some cutting-edge technology that will enhance its ability develop a clear picture of what is happening. This includes instrument packages mounted on moorings; mobile, autonomous “gliders”; underway ship surveys; standard ship-based station sampling; and satellite measurements of sea surface temperature and ocean color.

Skidaway Institute researchers (l-r) Catherine Edwards, Trent Moore, Julie Amft and Jim Nelson examine a glider.

Three moored packages will be deployed to provide continuous measurements of water properties and currents through the winter months. One mooring will be placed at 35 meters of depth, the approximate position of the shoreward edge of the winter bloom.

Two more packages will be placed in approximately 75 and 150 meters of water, with the 75 meter mooring equipped with an instrument package called a SeaHorse. Powered by wave motion, the Seahorse moves up and down its mooring wire, taking measurements throughout the water column. A telemetry system in the surface mooring periodically reports its observations.

The research team will also use another high-tech tool, autonomous underwater vehicles, also called gliders.

Skidaway Institute researchers lower a glider into a tank of water to adjust buoyancy and trim. (l-r) Trent Moore, Dongsik Chang, Charles Robertson and Julie Amft

Two of these torpedo-shaped vehicles, equipped with sensors and recorders, will provide the ability to collect observations under all conditions, including during winter storms when ship operations are not possible. The gliders will survey across the study area, taking and recording measurements as they go. From time to time over the four to five week missions, they will surface, report their data by satellite phone and receive instructions as needed.

The gliders will be controlled from shore with an autonomous glider control system co-developed by Fumin Zhang at Georgia Tech Savannah. Two Georgia Tech-Savannah graduate students, Klimka Szwaykowska and Dongsik Chang, are developing algorithms to optimize the glider sampling given real-time data collected by satellite, the SeaHorse profiler and the gliders themselves.

Catherine Edwards (r) and Dongsik Chang work on the tail of a glider while Klimka Szwaykowska looks on.

Members of the research team will spend much of the winter of 2012 aboard the Skidaway Institute research vessel R/V Savannah, conducting experiments and collecting data.

Armed with a better understanding of the physical processes that “fertilize” the outer shelf and how phytoplankton take advantage of the nutrient input, the research team will be able to answer larger questions about how biology and physics interact in Long Bay.

The project will run for three years.