As Bermuda braces for Gonzalo, underwater glider studies hurricane impact
A marine scientist is deploying an undersea glider to take measurements during the Category 3 storm, which is expected to hit Bermuda. Hopefully, the rare underwater perspective will yield insights that can be used to develop forecasting models.
Hurricane Gonzalo, the second major hurricane in the Atlantic this year, is bearing down on Bermuda, while kicking up dangerous surf from the Virgin Islands to the southeastern coast of the United States.
High waves and rip currents are expected to affect the rest of the East Coast as Gonzalo moves northwestward, roughly tracking the East Coast of North America, though well offshore.
Forecasters at the National Hurricane Center in Miami say they expect the storm to reach Bermuda later today, bringing from 3 to 6 inches of rain to the island. Although forecasters in Miami have no formal estimate of the storm surge Gonzalo could generate, the surge could reach up to 10 feet, based on the island's encounter with hurricane Fabian in 2003.
At 11 a.m. Eastern Daylight Time, Gonzalo's eye was about 125 miles southwest of the popular vacation spot, still in its “beach season.” The storm is generating maximum sustained winds of 126 miles an hour, placing at the high end of the wind range for a Category 3 hurricane, capable of inflicting heavy damage to homes and small buildings.
Although Gonzalo is still dangerous, it has weakened from a Category 4 storm over the past several hours.
Hurricane-force winds extend up to 60 miles from the storm's center, while tropical-storm force winds are appearing out to 175 miles from the eye. The storm is expected to slowly begin weakening.
Most of the islands preparations appeared to be wrapping up early Friday, with normally bustling streets and sidewalks empty during what otherwise would have been the morning rush hour, according to reports in the Royal Gazette, Bermuda's only daily newspaper.
The Royal Navy has sent a frigate, the HMS Argyll, to Bermuda with supplies to help with post-storm recovery, according to the island's premier, Michael Dunkley.
As residents brace for the storm, it also is providing an unexpected opportunity to gather hard-to-get information on the processes that feed hurricanes, notes Ruth Curry, a marine scientist at the Bermuda Institute of Ocean Sciences.
Dr. Curry has dispatched Anna, an undersea glider, to take measurements of temperatures, salinity, pressure, and oxygen levels as Gonzalo passes over it.
“Hurricanes feed off of ocean heat energy, and leave a wake of cooler surface waters behind,” she explains in an e-mail. “What that process actually entails is not well understood yet, although this has a big impact on the ability to forecast the path and intensity of tropical storms.”
The hope is that by gathering a series of measurements over the 10 hours that hurricane-force winds are expected affect the area, Anna's perspective from underneath the water will yield additional insights into the interplay between the ocean and the storm.
By uncovering the physics behind this interplay, researchers and forecasters can work them into climate- and hurricane-forecasting models. This could improve the accuracy of intensity and track forecasts, Curry explains.
“This is a very powerful hurricane, and these glider measurements are providing a unique opportunity to 'see' what is happening under the sea surface,” she writes. “Quite remarkable, to say the least!”