Category 4 storm saildrone data reveals hurricane evolution

Motion sickness: activated.
GIF: Saildrone / NOAA

While we average people enjoyed the incredible images captured by a drone floating in the middle of a Category 4 hurricane, scientists looked at the data. And now they’re ready to share some of the findings and ideas on how the fiercest storms on Earth can gain strength.

The results were presented at the American Geophysical Union’s annual meeting as part of a series of talks ending the year of research for Saildrone. The company has worked closely with federal scientists to deploy its fleet of marine drones from the tropics to the poles. One of their most daring exploits in 2021 was to send one of their autonomous vehicles into the mouth of Hurricane Sam.

The powerful storm luckily stayed far offshore for most of its life, although its outer edges peeked into Bermuda. But the Saildrone 1045 didn’t need to be close to shore to operate; vehicles can pass through virtually any corner of the sea. And the researchers directed it directly into Sam one day at the end of September, like the storm was experiencing rapid intensification, a meteorological term for when storms see winds increase by at least 35 mph (56 km / h) in 24 hours. The trip was a first for Saildrone vehicles, which have never entered such a fierce storm.

“I told everyone, ‘If this vehicle can survive a hurricane, then it would be a great achievement,” said Chidong Zhang, director of the Oceanic Climate Research Division of the Federal Laboratories of the United States. Pacific marine environment, in a statement. declaration. “The whole mission exceeded my expectations.”

The drone returned unreal images as it was rocked by towering waves. The search team reported that he rolled over several times while sliding up and down in the face of 50-foot (15-meter) swells. He didn’t just survive. He thrived, transmitting images and data to the shore crew.

Some of this data shocked researchers and made them wonder if an instrument had failed. Saildrone data showed a lingering pool of hot water clinging to the surface, giving Sam even more fuel to power up. Hurricane winds typically lift the ocean, drawing cooler water below the surface. This mixture can help slow the intensification of hurricanes.

Not only was the water warm under Sam’s heavy thunderstorm, it was also less salty. Using data from a buoy in the area, researchers were able to confirm that the drone’s instruments were performing very well. They also gleaned the probable source: the Amazon River. Ocean currents transported warm, less salty – and therefore less dense – water to the middle of the Atlantic, where he acted as a cover over the ocean. Researchers too deployed underwater drones called gliders and The Hurricane Hunter plane with the Saildrones, adding to the data stack.

Scientists will continue to comb through the data over the next several months, but preliminary results show how the natural processs can influence hurricanes and even benefit from the effects of climate change. Other research has shown how the ocean becomes no longer laminated due to surface heating and generally the creation of an environment where storms can intensify faster. (It also increases the chances of prolific hurricanes and tropical storms and sea ​​level rise, so really, there is no shortage of misfortunes.)

SD 1040 captured this photo of a wall of water in strong winds and waves on the edge of Tropical Storm Wanda (after the storm weakened to a post-tropical low) on November 7, 2021, off the coasts of Delaware.

SD 1040 captured this photo of a wall of water in strong winds and waves on the edge of Tropical Storm Wanda (after the storm weakened to a post-tropical low) on November 7, 2021, off the Delaware shores as she made her way to Newport, Rhode Island, for recovery.
Photo: Saildrone

“I like to look at him like [global warming is] increasing the maximum intensity that a hurricane can reach, ”said Greg Foltz, physical oceanographer at the Atlantic Federal Oceanic and Meteorological Laboratory, in a statement. “It’s not that every hurricane is going to increase in intensity, it’s that under the right conditions, a hurricane that would normally reach a wind force of 150 mph could reach 160 mph. This creates the potential for more storms. strong.

Getting a view of the interior of a hurricane, even one influenced by a natural heat source, could provide researchers with valuable information for future predictions. Saildrone’s research team also sent their unmanned vehicles to five more tropical cyclones in the Atlantic this year to understand the rapid intensification. Now it’s all about making the most of that data so that we can prepare for whatever the future holds.