UMCES glider on mission to assist hurricane forecasting

September 14, 2017

With hurricane season in full swing, the University of Maryland Center for Environmental Science has launched its underwater glider "Striper" off the New Jersey coast, just north of Atlantic City. This autonomous underwater vehicle is patrolling the East Coast during hurricane season to collect data that can improve intensity forecasts.

This flight is part of a MARACOOS (Mid-Atlantic Regional Association Coastal Ocean Observing System) plan to track the “cold pool” extending from Cape Cod to Cape Hatteras, explained Bill Boicourt, professor emeritus for UMCES who oversaw the launch.

"This three-season subsurface cold band is an important habitat for fisheries and a potential heat sink to damp hurricanes propagating up the Middle Atlantic Bight, but it is hidden below the surface unless hurricanes (such as Irene in 2011) come along and stir the cold water to the surface where it can shut down the heat engine," he explained. "Irene’s intensity was overpredicted by 50 percent because the time evolution of ocean surface temperature is not included in the forecast models."

The National Weather Service called for a national glider plan to maintain a fleet of gliders patrolling the East Coast shelf during hurricane season to help with forecasting.

Striper swims out into the ocean like the fish it's named for. It has a streamlined, torpedo-like hull stretching about 2 meters long and can change its buoyancy like a submarine, gliding upward and downward as it profiles with a suite of sensors. Striper made its way toward the shelf break, and turned toward Delaware Bay. Then it's off to the edge of the shelf south of Baltimore Canyon, and finally to Wachapreague, Virginia for retrieval. The glider will take about a month to complete its route.

Follow the gliders in real time

Using Google Earth, you can follow Striper in real time. Follow these steps:

1. Visit this site and under the title “Deployed Glider KMZ Files,” click on the first Google Earth icon (under the word Gliders). This will allow you to download a kmz file you'll need to view the gliders.

2. Open Google Earth (This works best if you use the application rather than the web browser version, so you might need to download it to your computer). In Google Earth, go to File, then Open, and select the kmz file you downloaded. Under the Places menu on the left-hand side of the screen, you will see listings for Striper and other gliders. Click on each to see where in the world these gliders are located.

3. You can also view graphics of real-time data on the original website where you downloaded the kmz file. Select the glider you want to know more about and then click “view imagery” to see the transect plots.

Striper's progress

As of Sept. 12, 2017, Striper was 116 kilometers off New Jersey, with about 7 km to go to the shelf-break waypoint. The image below reveals the cold pool over the outer shelf (which reaches its minimum temperature during the summer season—it’s winter water propagating down from the Gulf of Maine and Georges Bank)—with temperatures that are still below 9C this late in the season, Boicourt said.

Striper’s launch was coordinated with UMass Dartmouth glider Blue, which launched off New Bedford, Massachusetts. Both gliders are intended to sweep four cross-shelf transects, with Blue repeating Striper’s offshore New Jersey transect as it comes in for retrieval, Boicourt said.

Rutgers University maintains the national glider data center and they are helping with Striper’s piloting. Chip Haldeman and David Aragon of Rutgers helped run checks on the glider before the launch and UMCES; Kurt Florez and Jason Beveridge enabled inter-institutional machine communication between UMCES' Horn Point Laboratory in Cambridge, Rutgers in New Brunswick, New Jersey, and the Virginia Institute of Marine Science in Gloucester Point.