A swarm of robots capable of studying detailed ocean dynamics are described in Nature Communications this week. The small, autonomous robots can record 3D movements of water that have been difficult to measure using traditional instruments, and may provide new insights into physical and biological phenomena in the ocean.

Some of the least-understood processes in the ocean, such as internal wave formation, occur beneath the surface at scales between a metre and a few kilometres. Observations of these dynamics require simultaneous sampling at multiple locations, a task that could be suited to swarms of current-following vehicles, Jules Jaffe and colleagues note. A five-hour deployment of 16 mini-autonomous underwater explorers, whose 3D trajectories are measured near-continuously, is shown to produce a high-resolution reconstruction of the movements of internal waves. The robots mimic formations observed in plankton, which demonstrates how this system can help to explain the influence of ocean dynamics on biological processes.

The authors propose that these small (1.5 litres in volume), relatively inexpensive vehicles could be used in conjunction with other observational tools to improve our understanding of interactions between physical dynamics and biological processes in the open ocean.