All eyes were on the gray water in the chilly, choppy waters of Alaska’s Resurrection Bay, seeking one thing only. It wasn’t a spout from a humpback whale cruising through this beautiful fjord. Also, not a sea otter snoozing on its back while eating a king crab.
Instead, everyone on board the Nanuq, a research vessel for the University of Alaska Fairbanks, was hunting for a 5-foot (1.52-meter) long bright pink underwater sea glider that surfaced.
The glider had recently completed its first nighttime mission. It was likely to be the first to have a big sensor for measuring carbon dioxide levels in the ocean.
The autonomous vehicle was placed in the Gulf of Alaska this spring. It was to provide a deeper understanding of the ocean’s chemistry in the era of climate change. It was designed to dive 3,281 feet (1,000 meters) and explore distant sections of the ocean. Measuring CO2 concentrations – a quantifier of ocean acidification — was largely done from ships, buoys, and moorings connected to the ocean floor until now. Therefore, the findings could be a huge step forward in ocean greenhouse gas monitoring.
Ocean acidification
“Ocean acidification is a process by which humans are emitting carbon dioxide into the atmosphere through their activities of burning fossil fuels and changing land use,” explained Andrew McDonnell. He is an oceanographer at the University of Alaska Fairbanks’ College of Fisheries and Ocean Sciences.
Oceans have greatly aided mankind by absorbing part of the CO2. Otherwise, the atmosphere would be much thicker, trapping the sun’s heat and warming the planet.
“But the problem is now that the ocean is changing its chemistry because of this uptake,” said Claudine Hauri. Hauri is an oceanographer at the university’s International Arctic Research Center.
Ocean acidification, which can hurt and kill certain marine life, is being studied using the massive amount of data acquired.
Some marine animals that make shells face harm from rising ocean acidity. This process has the potential to kill an organism or make it more vulnerable to predators. (Xanax)
Sensor
Hauri and McDonnell, who are married, collaborated with engineers from Cyprus Subsea Consulting and Services. They provided the underwater glider and 4H-Jena. It is a German business that donated the sensor implanted into the drone, over the course of several weeks this spring.
Most days, researchers from the coastal hamlet of Seward took the glider farther and farther into Resurrection Bay to undertake testing.
A crew member saw it bobbing in the sea after its first nocturnal flight, the Nanuq — Inupiat for polar bear — backed up to allow workers to haul the 130-pound (59-kilogram) glider aboard the ship. The sensor was then removed from the drone and hurried into the ship’s cabin to be uploaded.
Consider the 6-inch (15.24-centimeters) diameter sensor as a laboratory in a tube. It has pumps, valves, and membranes working to separate the gas from the seawater. It analyzes CO2 and logs and keeps the results in a temperature-controlled environment. Batteries power many of the sensor components.
The sensor is available on any ship or lab that uses CO2 measurements because it is the industry standard.
Gliders to measure CO2 directly
Hauri said using this was “a huge step to be able to accommodate such a big and power-hungry sensor, so that’s special about this project.”
“I think she is one of the first persons to actually utilize (gliders) to measure CO2 directly, so that’s very, very exciting,” said Richard Feely. Feely is a senior scientist with the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory in Seattle. Hauri, he added, was a graduate student when he took her on the first acidification cruise he led in 2007.
The problem, according to Feely, is to do measurements on a glider with the same level of precision and accuracy as tests on ships.
“We need to get confidence in our measurements and confidence in our models if we are going to make important scientific statements about how the oceans are changing over time and how it’s going to impact our important economic systems that are dependent on the food from the sea,” he says. Thus, noting that acidification impacts are already visible in the Pacific Northwest on oysters, Dungeness crabs, and other species.
Researchers in Canada previously mounted a smaller, prototype CO2 sensor to an underwater drone in the Labrador Sea. But it failed to achieve the criteria for ocean acidification observations.
Nicolai von Oppeln-Bronikowski is the Glider Program Manager at the Ocean Frontier Institute at the Memorial University of Newfoundland. Nicolai said, “The tests showed that the glider sensor worked in a remote-harsh environment but needed more development.”
The two teams are “just using two different types of sensors to solve the same issue, and it’s always good to have two different options,” Hauri said.
“What’s going on in the ocean”
The underwater autonomous drone does not have a GPS device. Instead, after its programming, it goes off on its own to navigate the ocean, understanding how deep to dive, when to sample, and when to surface and send a locating signal so one can retrieve it.
During the drone experiments, the US research vessel Sikuliaq, which the National Science Foundation owns and administered by the university, completed its two-week trip in the Gulf of Mexico. It was to collect carbon and pH samples as part of an ongoing study in the spring, summer, and fall.
Those methods limit to collecting samples from a fixed place. Bur the glider will be able to go throughout the ocean. It will offer researchers with a lot of information about the ocean’s chemical composition.
The goal is to have a fleet of robotic gliders operating in oceans all over the world one day. So, it offers a real-time view of current circumstances and a better approach to predicting the future.
“We can … understand much more about what’s going on in the ocean than we have been before,” McDonnell said.
