Giant blue jet
caught on film
Blue jets connect Earth's electric circuit.
14 March 2002
captured in Puerto
Rico suggest that
blue flashes of light,
much like lightning,
feed energy from
thunderstorms up into
ionosphere - a
air some 70
kilometres above the
Some researchers suspect that such
phenomena may also fix nitrogen for plants
to use and interact with the ozone layer2.
The images, taken in September 2001,
show the largest blue jet ever to be caught
on camera. "It really was a gigantic flash,"
says Victor Pasko of Pennsylvania State
University, who led the observation team.
"With the naked eye you could even see it
rising," he recalls.
Blue jets are often associated with
thunderstorms, but until now were thought
to be relatively small. The Puerto Rican jet
stretched from the top of a small
thunderstorm to the lower edge of the
ionosphere, filling an estimated 6,000
cubic kilometres of atmosphere.
Flashes this big might explain the
300,000-volt difference between the
charge of the ionosphere and the ground.
Physicists have long agreed that something
must link the two regions to complete the
global electrical circuit (GEC). Until the
latest film, nothing had been seen that
reached high enough from the cloud tops to
do the job.
"We knew the currents were there, but
there was no visual evidence" says Davis
Sentman, the physicist at the University of
Alaska in Fairbanks who discovered blue
jets in 1994. The film "really advances the
science in this field", he says.
That the sighting was associated with the
kind of small, localized storm common
worldwide, suggests that large blue jets
could also be common. If so, they might
influence atmospheric chemistry: their
electrical energy could encourage gases to
react with one another. "The effect may be
there but we don't know if it's dramatically
important," admits Pasko.
Sprites, elves, trolls and pixies
In the past decade,
allowed scientists to
bear names that
would be more at
home in a Tolkien
novel than a physics
blue jets and
crawlers, trolls and
pixies are all fleeting electrical discharges
that accompany thunderstorms.
All these phenomena are hard to spot, as
they last for less than a blink of an eye and
are obscured from below by cloud. They
can be glimpsed along storm fronts and
from aeroplanes flying above the clouds.
Sprites, which might also help to maintain
the GEC, work a bit like blue jets in
reverse. They are pink, or sometimes red,
and occur when current from just below the
ionosphere moves downwards towards
thunderstorms. As with jets, this current
excites atoms along the way, causing them
to emit light.
1.Pasko, V. P., Stanley, M. A.,
Mathews, J. D., Inan, U. S. & Wood,
T. G. Electrical discharge from a
thundercloud top to the lower
ionosphere. Nature, 416, 152 - 154,
2.Mishin, E. Ozone layer perturbation
by a single blue jet. Geophysical
Research Letters, 24, 1919 - 1922,
© Nature News Service / Macmillan
Magazines Ltd 2002
Sorry for the formatting. The Global Electrical Circuit. More proof
of Gaia as a living organism. That is if you believe that life is an