Reported April 2007

BACKGROUND: Last year, a caravan of weather balloons made meteorological history by marking the first-ever deployment of a new airborne weather-observing platform, called a driftsonde. Driftsondes are weather instruments connected to a balloon that "drifts" through the atmosphere collecting data. Nearly 300 gathered data from critical regions in the atmosphere that serve as breeding grounds for some of the worst hurricanes in the United States.

HOW IT WORKS: The driftsonde setup includes a super-pressured balloon that slowly inflates as it reaches the upper atmosphere; a parachute that allows the unit to descend safely when needed; a corner reflector to help airplane radar spot the unit and avoid a collision; a gondola holding communications equipment for tracking; and another gondola holding 35 weather measurers. The tracking system also receives assistance from the Global Positioning System (GPS). The weather measurers are strewn along the path the balloon takes in the upper atmosphere, released about twice a day. As they fall, they sense the weather conditions during the 20-minute descent, and this data is radioed back to the balloon, and then transmitted via satellite to the researchers at the National Center for Atmospheric Research (NCAR). The new system is called Miniature In-situ Sounding Technology (MIST), and it is a highly compact instrument, about the size of a small bottle of water and weighing a mere five ounces.

CHALLENGES MET: Each driftsonde had to be able to withstand several days of extreme cold in the upper atmosphere, averaging -80 degrees Fahrenheit, as well as the intense sunlight typical of the high, thin stratosphere. Using the balloons also had to be affordable and practical, so the system required low-cost, lightweight, off-the-shelf instruments that could operate reliably in low pressure and in temperature extremes, while consuming very little power. Because of their flexible and relatively inexpensive nature, scientists believe that driftsondes may soon become a very popular way to monitor and study many types of weather across the globe -- even in very far-off regions.

The American Meteorological Society contributed to the information contained in the TV portion of this report.

If you would like more information, please contact:

American Meteorological Society
Boston, MA 02108-3693
(617) 227-2425
http://www.ametsoc.org

David Hosansky
Public Information
University Corporation for Atmospheric Research
(303) 497-8611
hosansky@ucar.edu

DID YOU KNOW?

Weather balloons are sometimes cited as the cause for reported UFO sightings.