OFFICIAL NASA PRESS RELEASE
Sprites observed outside the U.S.
Headquarters, Washington, DC June 7, 1995
Geophysical Institute, University of Alaska, Fairbanks
SPRITES CONFIRMED OVER STORMS OUTSIDE U.S. FOR FIRST TIME
NASA researchers have captured on videotape the
first conclusive evidence that the mysterious flashes of
red light called sprites -- which extend up to 55 miles
above electrical thunderstorms -- are not limited to the
The research team from the Geophysical Institute of
the University of Alaska, Fairbanks, recorded the unusual
flashes above thunderstorms near the equator in South
America last February and March. Previously, they had seen
the recently discovered sprites above storms only in the
U.S., leading some scientists to question whether or not
they occur in other parts of the world.
Geophysical Institute researchers Davis Sentman,
Gene Wescott and Daniel Osborne used special low-light-
level cameras aboard a Westwind-2 jet aircraft to record
the brief flashes. The flights, part of a NASA-sponsored
investigation into the phenomenon, were coordinated with
the Peruvian Air Force. The researchers recently completed
an analysis of the footage gained during their flights.
In form and in visual appearance, the sprites over
South America look similar to flashes recorded by the team
over storms in the central U.S. last summer. About 500
sprites were recorded last June and July, many on color
video for the first time. None of the sprite groups seen
this winter over South America were as large or as intense
in color as some of the larger groups recorded over the U.S.
Less intense thunderstorms may have contributed to
the smaller number and desultory appearance of the sprites
in South America. In the southwestern-central U.S., the
storms form along a quickly moving frontal system, but the
convective storms in South America are nearly stationary;
they tend to grow in place, develop slowly into large
systems like boiling water, then dissipate.
Some scientists had speculated that sprites might
not exist over equatorial regions because thunderstorms
there frequently do not get larger than about 100 miles,
which some thought was the minimum size needed to produce a sprite.
Pilots and others also have reported seeing blue or
greenish columns propagate upward at great speed from the
top of thunderstorms. Wescott and Sentman were the first
to report the video capture and the characteristics of
"blue jets" from 1994 flights over the U.S. No blue jets
were seen over South America.
Sprites can be seen from the ground after dark with
the unaided eye under the right conditions. To encourage
pilots and others to report sprite sightings around the
world, Sentman is establishing a Sprite Watcher's Homepage
on the World Wide Web. The homepage will give brief
information about sprites, the conditions needed to view
sprites from the ground or air, and simple directions to
follow when recording a sighting. All public sightings
will be incorporated into a scientific database, and then
displayed on a global map for Web users.
Researchers from government laboratories, universities,
and Federal agencies will continue to investigate sprites and other
phenomena associated with thunderstorms this summer during two main
campaign efforts. A team from the Geophysical Institute will observe
storms from Colorado mountain tops to support optical observations
of sprites made from the Yucca Ridge Field State east of Fort Collins,
CO. Research into what causes sprites will be made using radio
frequencies, radar, and other measuring techniques at additional
sites across the eastern half of the U.S.
More than two dozen scientists from across the
country will participate in a second major campaign, which
will focus on thunderstorms around northern Florida.
Facilities and capabilities at NASA's Kennedy Space Center
will be used in the study.
EDITOR'S NOTE: Individuals interested in participating
in the sprite research or receiving further information via
the internet can access the
Sprite Watchers Homepage.
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