A research ship slows to a crawl somewhere between Guam and the Solomon Islands. Barely a drift at two knots. A cylindrical robot is lowered into the nearly artificially blue water as the crew assembles close to the stern. No fanfare is present. There was no press release. After a few pictures and the gentle mechanical clunk of equipment, the float disappears below the surface, starting a journey that will last longer than the actual expedition.
This is how ocean science is undergoing a quiet revolution. slowly. without any headlines. One float at a time.
The robots in question are a part of the Global Ocean Biogeochemistry array, or GO-BGC as researchers refer to it. They are part of a larger family of over 4,000 Argo floats that are dispersed throughout the world’s oceans. Six of them were deployed in the tropical western Pacific during the recent NA172 expedition aboard the E/V Nautilus. This region of the ocean receives little attention despite its significant impact on global climate patterns. Each float descends about 1.25 miles, gathers information while returning to the surface, transmits it all to satellites, parks at 3,300 feet, and drifts for ten days before repeating the process. for many years.
It’s difficult not to appreciate the design’s simplicity. These devices function in equatorial heat, storms, and currents that would subdue the majority of research vessels. Speaking with the scientists involved, it seems like the floats are accomplishing things that humans are just not capable of, at least not on a large scale. Scripps Institution of Oceanography staff research associate Melissa Miller has joked that she is gradually being replaced by robots. Because it is partially true, the line lands. Measuring nutrients and dissolved oxygen from samples of seawater, she used to perform the lab work herself. These days, the floats do a lot of it on their own, producing datasets that are unmatched by a single research career.
Here, the economics are subtly astounding. Tens of thousands of dollars are spent on each biogeochemical float, and the total cost of all programs is in the hundreds of millions—possibly even higher when you account for international coordination, ship time, and supporting infrastructure. When you consider everything, the term “billion-dollar buoys,” which some have begun to use, isn’t particularly exaggerated. However, it is hard to overestimate the return on that investment. In addition to tracking ocean acidification and the amount of carbon the oceans are absorbing from the atmosphere, the data also helps researchers understand penguin populations by tracking chlorophyll blooms. In one study, float data was used to track bird behavior. The system was not created with penguins in mind. The data keeps finding new applications because that’s just how these things operate.
In ways that don’t always make headlines, the western Pacific is important. It’s where El Niño starts, where coral systems are at risk, and where some of the most significant ocean-atmosphere exchanges take place. Policymakers and investors seem to think that solar panels and electric cars are the answer to climate change, and that’s true, but the unglamorous process of measurement is what makes any of those solutions verifiable. We would be speculating if it weren’t for the floats.
One small detail from the expedition sticks in my memory. During the trip, Miller used a life-size cutout of a float, known as Floaty, to wave at classrooms via video calls. Through an outreach program, students from all over the world adopted the six floats, gave them names, and agreed to monitor them for the following five years. With the cardboard version, the crew continued to take pictures. It’s an odd picture. A cardboard robot is positioned against a ship’s rail as its actual counterparts start ten years of silent work under the waves.
Another question is whether the public ever takes notice. Most likely not. However, the floats will continue to function.
