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NOAA HELPS AROUND THE WORLD BALLOON FLIGHT

July 2, 2002 — Steve Fossett, who just successfully completed his solo attempt to fly around the world in a hot air balloon, knows which way is up, but he needed NOAA's help to tell him which way the wind blows. (Click image to see sample of NOAA trajectory forecasts.)

Fossett's team of meteorologists were guided by a computer program used to indicate where stuff in the air—such as volcanic ash—is coming from and where it's going. For balloonists, that means that they can track wind currents, essential information when one is dependent on those currents to keep on course. NOAA's Air Resources Laboratory in Silver Spring, Md., has offered this information to balloonists attempting manned long-distance flights since 1981.

"Much of what we do looks at things that affect human health, so it's nice to do things that celebrate the human spirit," said Richard Artz, deputy director of NOAA's Air Resources Laboratory. "These sorts of events are also a nice way of confirming that our products do what they are supposed to do."

The meteorological forecasts relied on the Hybrid Single Particle Lagrangian Integrated Trajectory model, or HYSPLIT for short, which tracks wind currents and anything that may be carried by the wind. In addition to HYSPLIT, Fossett's meteorologists used data supplied by the balloonist, such as his exact position and the local wind speed and direction. Via the web, the HYSPLIT model can provide forecasts where the balloon would go for up to the next 12 days.

HYSPLIT is commonly used to trace wind currents and learn where particles or gases in the air came from, but balloonists appreciated the system's ability to predict wind patterns in real time, which is just what they needed.

Also key to Fossett's success were data from two NOAA National Weather Service numerical models (AVN and ETA), used for global and regional weather prediction by the national and international weather community.

Fossett's meteorological team was headed by Luc Trullemans of the Royal Meteorological Institute in Belgium. Trullemans has worked on several balloon flights, including the 1999 record-breaking around-the-world flight of Bertrand Piccard and Brian Jones, where HYSPLIT was also used.

Getting ready to cross the Pacific, Piccard and Jones wanted to go north for faster winds, but the HYSPLIT showed slower winds to the south that were predicted to become stronger over the next few days.

Heeding the computer model, the balloonists headed south, which was wise, because the northern route was racked with violent thunderstorms that "could have torn the balloon apart and sent us hurtling into the sea," Piccard and Jones wrote in their account of the trip, "Around the World in 20 Days."

The system went online in 1997 through the Real-time Environmental Applications and Display System (READY) Web site and was awarded the NOAA Administrator's Award in 1998. After September 11, it was restricted for use by registered users only.

ARL has followed more than two dozen manned balloon flights since 1981, many of them attempting to fly non-stop around the world. Not all were successful. A chart that is kept by ARL notes events such as "hit hill," "Himalaya barrier," and "participation terminated" and gives a brief analysis of the outcome.

Relevant Web Sites
NOAA's HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) Model

NOAA's Air Resources Laboratory

NOAA Research

Media Contact:
Jana Goldman, NOAA Research, (301) 713-2483

 

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