Just sit right back and you'll hear a tale -- a tale of a scientific trip. It started from San Francisco's bay aboard a tiny ship. The weather started getting rough; the tiny ship was tossed.
And though this ship did not have a fearless crew, it did not get lost.
For those of you still reading...
The Papa Mau, a surfboard-sized robotic submarine developed by a Sunnyvale-based company, arrived in Australia last month after a year-long voyage across the Pacific Ocean that started in the San Francisco Bay. The journey covered 9,000 nautical miles and set a new world record for the longest distance traveled by an autonomous vehicle.
During the trip, the craft also gathered information about rough weather that wasn't detected by a satellite.
On what appeared to be a calm, sunny day last February, Papa Mau transmitted data indicating rough weather—six- to 7.6-meter rolling seas and winds blowing at 50 knots.
“There was not a cloud in the sky, nothing was on the satellites,” says Bill Vass, CEO of Sunnyvale, Calif.-based Liquid Robotics, a provider of ocean data services for shipping, energy and environmental companies. “And we said, ‘Oh, there must be something wrong with [the submarine’s] sensors.’ But when all four robots saw [the waves], we turned on the cameras. It was pretty astounding.” Nearby, an unfortunate sailboat lost its mast and was rescued by a Dutch freighter. “Besides that sailboat, the freighter, and us, no one would have seen those waves,” Vass adds.
Vass told Scientific American that the Papa Mau's findings highlight the inaccuracies of satellites that work to detect conditions on the ocean from more than 200 miles above the Earth's surface.
After comparing satellite data with his robots’ findings, Vass believes satellites detect surface shear, which comes from winds and broad currents. There are two dimensions to surface shear. One is the difference in currents at the ocean’s surface compared with those flowing at lower levels of the water column. The second occurs when two currents collide and generate smaller localized eddies and turbulence. Both are important to know when determining circulation and its effect on shipping energy usage and fuel consumption.
Vass and others from Liquid Robotics talk more about the Papa Mau in this video from the company.