As Hurricane Irma, one of the strongest Atlantic storms ever recorded, rampaged through Florida, floodwaters from Harvey, the wettest tropical cyclone to hit the United States mainland, receded, sending trillions of gallons of freshwater into the Gulf of Mexico. That influx is altering the salinity of the Gulf, potentially triggering an algal bloom that could harm marine life, including valuable commercial species.
Yet real-time data on the phenomenon is lacking. Though a farmer can find out the pH of every row of her crops in Iowa while sitting in a Broadway theater, and a homeowner can crank up his hot tub from a window seat on a 787, fishers are lucky to know if the weather will be too stormy to go out a week from now – and must rely on little better than a hunch to know where the fish will be. The mobile phone revolution has made it cost-effective to connect remote sensing devices on land to the internet, providing real-time data and the ability to manage resources. Yet the ocean – covering two-thirds of the Earth’s surface – is by comparison a black box.
That’s beginning to change as scientists, governments and the private sector seek to collect more data from the ocean for climate change research, security, resource extraction and other purposes. Liquid Robotics, a Silicon Valley-based company that manufactures an autonomous sea-faring robot called the Wave Glider, dubs it the “Digital Ocean” – an effort to build a vast network of remote, relatively low-cost instruments at sea that are capable of communicating with one another and with satellites, airborne drones and onshore facilities
“It’s a set of standards and systems, the component building blocks to understand biology, hydrology and geology underwater so that we can watch oceans the way we watch land,” said Graham Hine, senior vice president and cofounder of Liquid Robotics, now a subsidiary of Boeing. “There’s a ton of information we need from the ocean, and this will let us be better custodians of its resources.”
The infrastructure of the Digital Ocean. (Courtesy of Liquid Robotics, a Boeing Company)
Powering itself with wave energy and solar panels, the Wave Glider can carry a sensor payload to collect data, sampling to a depth of 30ft (9m). That’s a very active zone biologically, but it comprises less than 1 percent of the ocean. Perhaps the Wave Glider’s most significant role in the Digital Ocean is therefore similar to that of a network router. Radio waves don’t travel well through water, and acoustic telemetry can’t carry much data. The Wave Glider links systems that use different modes of communication: Sensors on the seafloor can transmit data on tectonic activity acoustically to a Wave Glider on the surface, which beams to shore via satellite or cellular connection. Such a system, for instance, could form the basis for a tsunami detection system.
On September 7, Liquid Robotics unveiled the next generation of the Wave Glider, which is capable of operating in more extreme ocean conditions and can carry heavier payloads and operate longer at sea on a battery with 40 percent more storage. The Scripps Institution of Oceanography at the University of California, San Diego, has operated an early version of the newest model off the coast of Iceland in waves higher than 33ft (10m), according to Liquid Robotics.
The next-generation Wave Glider. (Liquid Robotics)
In the South Pacific, Liquid Robotics worked with the United Kingdom’s Foreign and Commonwealth Office, the Pew Charitable Trusts and a U.K satellite company to deploy Wave Gliders to patrol the remote Pitcairn Islands rather than dispatch expensive planes and ships to the region.
Organizations such as the Ocean Tracking Network (OTN) and UNESCO’s Global Ocean Observing System have been leaders in deploying remote sensing equipment to build a global telemetry capability.
“As we intrude more and more into the ocean and make more and more use of it we’re going to have to manage things better than before,” said Fred Whoriskey, executive director of OTN, which is building a global network to track marine species. “We’re going to need a monitoring system to feed data to managers who need instantaneous access to all sorts of precise information.”
OTN, housed at Dalhousie University in Halifax, Nova Scotia, has for years deployed various forms of telemetry, including biologging, where a tracking device is placed on the back of a marine animal. It carries onboard sensors that determine the length of the day, which allows for calculation of latitude and longitude; pressure, which tells how deep the animal is underwater; and water temperature. But that’s only useful if the animal is later recovered. A second class of sensor emits a sonic ping that’s picked up when the animal passes within range of a receiver, either a stationary one or a vehicle such as a Wave Glider. The newest development in fish tags is one that dislodges itself as its battery is about to run out, pops to the surface, and transmits all the data it has collected to a satellite.
The organization also deploys Wave Gliders and a submersible autonomous vehicle called a Slocum. “You tell it to record temperature, depth, salinity,” Whoriskey said. “We’re working on acidification sensors, gas sensors for carbon – whatever you’d like to include and it will tell you what’s going on at various depths. That’s a gold mine of information about the structure of the water column.”
He pointed to weather forecasting and marine safety as other areas that will benefit from the development of the Digital Ocean. “With more data, insurance companies and developers can take preventive measures and policymakers can impose conditions on what’s being built and make it ready for the climate we’re going to have to survive in,” he said.