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 An international team including scientists from MARUM discovered ongoing and future tropical diversity decline
26.05.2020 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

nachricht The lower mantle can be oxidized in the presence of water
25.05.2020 | Science China Press

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

Im Focus: NASA's Curiosity rover finds clues to chilly ancient Mars buried in rocks

By studying the chemical elements on Mars today -- including carbon and oxygen -- scientists can work backwards to piece together the history of a planet that once had the conditions necessary to support life.

Weaving this story, element by element, from roughly 140 million miles (225 million kilometers) away is a painstaking process. But scientists aren't the type...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New double-contrast technique picks up small tumors on MRI

26.05.2020 | Medical Engineering

Increased Usability and Precision in Vascular Imaging

26.05.2020 | Life Sciences

Sugar turns brown algae into good carbon sinks

26.05.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>