The earth’s oceans cover 70 percent of the planet’s surface, so it’s no surprise they end up a receptacle for all kinds of things that move on the soil. Controversy — for example, the oceans’ status as a temperature sink — has made research into ocean currents and temperature a primary battleground for debate over climate change.
In the effort to better understand seawater temperatures and the movement of ocean currents, the oceans have also become home to some 3,000 floating measurement devices, called “drifters.” These myriad devices, designed by different researchers with differing objectives, all conform to one standard: the Argo standard. Even as Argo expands ever further into the ocean depths, new systems are coming into place, along with new controversies.
The Argo system itself helped fuel a significant climate science controversy over the past two decades: the so-called global warming “hiatus,” in which the rise of ocean temperatures appeared to slow dramatically. It was, University of California, Berkeley researchers now say, the result of moving from inferior shipboard measurement systems, to autonomous systems like the so-called drifters, which measure the water’s temperature before it has been heated by proximity to a ship’s engine.
In 2016, researchers brought online the most ambitious effort yet to track and understand ocean water temperatures and the patterns to its currents: The U.S. Ocean Observatories Initiative (OOI), spanning the Atlantic, Pacific and Southern Oceans, joined to three similar Canadian facilities in the Arctic and Pacific Oceans. Its centerpiece is a Pacific research installation called the “Cabled Array,” a 900-km-long cable connecting a base in Oregon with seven submarine nodes.
The Cabled Array’s equipment measures seismological activity, ocean currents and chemistry, especially around hydrothermal vents, where superheated, mineral-laden water emerges from the sea floor. These vents support very unusual forms of life, which are not found in any other habitat, and their data is part of the fire hose of information the OOI will funnel to researchers.
That’s proven controversial, and not just because of the debate over climate change research. OOI’s seven observatories cost $385 million in U.S. taxpayer dollars to make, and the data they produce will be shared openly with researchers from around the world. That’s made adoption by the scientific community tricky, as some worry they’ll work on a discovery, only to find themselves beaten to the punch by a competing research team.
One proposed lure to researchers was to put equipment on Axial Seamount, an undersea volcano about 480 km west of Oregon that is poised to erupt. It’s a rare opportunity to view an underwater eruption live. “There is nothing like a firework display to attract a crowd,” as the Economist noted dryly in 2015.
OOI’s live data streams came online last June, and extensions are already underway, connecting the network of tethered and floating measurement devices to new nodes in the Gulf of Alaska and on the Northeast U.S. Continental Shelf.
Even as that’s happening, new methods of tracking the movement and temperature of ocean waters are emerging high above the surface of the water. Robert Tyler and Terence Sabaka outlined a project to the American Geophysical Union’s meeting in December 2016, in San Francisco: follow the minute changes in the Earth’s magnetic field generated by the movement of ocean water.
NASA’s Aqua, designed and built by Northrop Grumman, is a satellite that tracks ocean currents and temperature from high up above. Recently, Aqua captured images of a phytoplankton bloom that made Jersey Shore waters temporarily look like the Caribbean.
Another satellite-based effort is measuring the movement of ocean surface currents using satellite images of the sun’s glittering reflection on the water. That could prove more accurate and useful for mariners and maritime construction companies that rely on wave predictions to work safely — but also add another valuable real-time stream of information into climate researchers’ efforts to understand the oceans.
Other researchers are doing the same thing using drones, taking instruments typically found aboard research vessels, aircraft and marine robots, and redesigning them to fit a drone’s limited payload. Oceanographer Christopher Zappa is one of them: His fleet of research drones flies low over Arctic ice, ranging wide to measure sea ice topography and movement.
Drones are a lot cheaper to operate than research vessels or massive cabled-together systems, but as the latest wave of controversy crashes over climate research, it remains to be seen if they’ll be able to rise above the stormy seas.