Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New thinking needed on atmospheric physics, study suggests

14.10.2002


Balloon Experiments Reveal New Information About Sprites



An atmospheric phenomenon called “sprites” could be pumping 50 times more energy into the upper atmosphere than was previously thought, suggesting our understanding of the global atmosphere is incomplete, according to University of Houston space physicists.

Sprites are large, brief flashes of light that occur very high in the atmosphere above large thunderstorms. Instead of discharging toward the earth like lightning, sprites soar upward above a thunderstorm and occur immediately following strong lightning strokes.


University of Houston physics professors Edgar Bering and James Benbrook, along with their students, collected sprite data during a balloon campaign in the summer of 1999 when several balloons equipped with special detectors flew high into the atmosphere – around 20 miles up – over Texas and Iowa. The experiments were intended to study the electromagnetic signature of the lightning strokes that produce sprites, as viewed from the perspective of the sprite.

“One of the more interesting things we discovered is that every lightning stroke tries to produce a sprite in the sense that it produces a similar but weaker electrodynamic pulse in the mesosphere,” Bering says.

The layers of the atmosphere consist of the troposphere, which extends from the ground to about nine miles up; the stratosphere, beginning just above the troposphere and extending to 31 miles high; the mesosphere, extending from the stratosphere to about 53 miles high; and the thermosphere, extending beyond the mesosphere to about 372 miles.

Previous research has shown that most sprites are produced by positive cloud to ground lightning strokes, which are much rarer than negative cloud to ground lightning strokes, Bering says. Negative cloud to ground lightning strokes are initiated by a large concentration of negative charge in the cloud base, which tends to induce an area of positive charge on the ground, resulting in a discharge of electricity – lightning. A positive lightning stroke is exactly the opposite, with a positive charge concentration in the cloud inducing a negatively charged area on the ground.

Bering and his colleagues also found that negative cloud to ground strokes produce a phenomenon that is not often observed from the ground, termed a sprite halo, which is basically a sprite precursor.

“We discovered that seven to ten times as many negative cloud to ground strokes produce sprite halos as do positive cloud to ground strokes. That, coupled with the fact that every cloud to ground stroke, positive or negative, tries to produce a sprite or sprite halo, indicates that the amount of energy being deposited in the mesosphere by these sprite processes and related processes exceeds what we thought the sprites did by a factor of 50.”

Bering says that amount of energy is comparable to the amount of energy the sun pumps into that same volume of atmosphere above the thunderstorm in daylight hours.

Bering will present an invited talk on the research findings at the World Space Congress 2002, to be held Oct. 10-19 in Houston.

The closest the balloon flights got to sprite-producing thunderstorms was about 300 kilometers, or 186 miles, which limited the amount of useful data the scientists could collect, Bering says. He cautions that the experiments need to be repeated because the results depended only on observations from a few storms.

However, he says the results of the balloon flights indicate our understanding of the mesosphere is incomplete.

“It means we actually have at certain times and latitudes about a factor of two discrepancy in the energy budget of the mesosphere. From the standpoint of global understanding of the atmosphere as a whole, a factor of two in an energy budget is nontrivial,” Bering says.

While the mesosphere does not directly affect weather on earth, and the altitude is too high for precipitation-producing clouds, some researchers are attempting the use mesospheric weather as a tracker for global temperature change.

Bering says the 1999 data suggests two avenues for future studies.

“We need to get closer to the storms, which requires both more balloons and also is a matter of luck, and put additional data collection equipment on board the balloons,” he says.

The National Aeronautics and Space Administration funded the 1999 balloon flights. Bering has submitted a proposal to NASA for additional balloon studies of sprites.

In January, Bering will begin a study of phenomena other than sprites when he sends three balloons into the air over Antarctica to study the electrodynamics of the polar ionosphere.
CONTACT: Edgar Bering, 713-743-3543; eabering@uh.edu

Amanda Siegfried | EurekAlert!
Further information:
http://www.uh.edu/admin/media/sciencelist.html.

More articles from Earth Sciences:

nachricht Early organic carbon got deep burial in mantle
25.04.2017 | Rice University

nachricht New atlas provides highest-resolution imagery of the Polar Regions seafloor
25.04.2017 | British Antarctic Survey

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Early organic carbon got deep burial in mantle

25.04.2017 | Earth Sciences

A room with a view - or how cultural differences matter in room size perception

25.04.2017 | Life Sciences

Warm winds: New insight into what weakens Antarctic ice shelves

25.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>