Featured Research

from universities, journals, and other organizations

First Estimates Developed Of Lightning-Associated "Sprites" -- Radio Signals Help Scientists Estimate How Many Occur In Thunderstorms

Date:
April 2, 1999
Source:
National Science Foundation
Summary:
For the first time, scientists have developed a reliable estimate of the number of "sprites" spawned by a single thunderstorm. Sprites, the luminous red glows that are the high-altitude companions of some lightning strikes, are the focus of a new study by researchers Steven Reising of the University of Massachusetts, and Umran Inan and Timothy Bell of Stanford University in California.

For the first time, scientists have developed a reliable estimate of the number of "sprites" spawned by a single thunderstorm. Sprites, the luminous red glows that are the high-altitude companions of some lightning strikes, are the focus of a new study by researchers Steven Reising of the University of Massachusetts, and Umran Inan and Timothy Bell of Stanford University in California. The team's findings appear in the April 1 issue of Geophysical Research Letters (GRL), published by the American Geophysical Union. The work was funded by the National Science Foundation (NSF), the U.S. Air Force, and NASA.

Sprites accompany roughly one in every 200 lightning strikes. They tower up to 55 miles above a thundercloud, occurring simultaneously with a lightning strike, and can be seen with the naked eye, sometimes from as far away as 400 miles. Sprites are electrical phenomena that appear above thunderclouds, reaching the lower ionosphere. These striated, glowing ribbons appear at several-minute intervals. They are found above all the major landmasses of the earth, according to Reising.

"Sprites are spectacular luminous evidence of electrodynamic coupling between the neutral atmosphere in which weather processes occur and the higher altitude (60-90 km) ionized regions of the earth's atmosphere known as the mesosphere and the lower ionosphere," explains Sunanda Basu, director of NSF's aeronomy program, which funded the research. "The importance of the new finding is that the radio signals produced by lightning discharges that lead to sprites are distinctly different from those due to other lightning discharges."

Researchers focused on a thunderstorm which occurred on August 1, 1996, in western Kansas, above which a total of 98 sprites were recorded in a 90-minute period. The team recorded the radio signals emitted by each lightning strike. For each visible sprite, they examined the corresponding radio wave measurements using custom-designed radio antennas and receivers. Researchers found that the lightning strikes that produce sprites also tend to carry a distinctive radio signature. The radio signals the team "read" were emitted by the lightning itself, rather than by its companion sprite. The information gleaned in the study may have a bearing on climate monitoring and atmospheric chemistry.

"This marks the first time that independent measurements not requiring video have been used to estimate the number of sprites produced by a single thunderstorm," said Reising. A typical lightning strike occurs in one-tenth of a millisecond. But those associated with sprites emit a much longer-lived electrical current. "These electrical currents last for at least several milliseconds," explained Reising. "In a relative sense, that's a long period of time, and radio measurements can easily tell the difference. We can't rely on video alone to count all the sprites, because many times, sprites are visually blocked by the clouds." Also, it would be nearly impossible, and extremely costly, to video-monitor every thunderstorm in the hemisphere, or around the world, he added.

Sprites do not interfere with spacecraft launches, aircraft or telecommunications satellites. However, chemical changes could be produced in the atmosphere by sprites. But in order to address that issue, scientists first need a reliable estimate of how many sprites actually occur. "Using four relatively low-cost receivers, you can count the number of lightning strikes and sprites in the Western hemisphere, 24 hours a day, and at very low cost," said Raising. "A storm in Brazil could be monitored by stations in California and Antarctica. You can do this from 12,000 kilometers away - a quarter of the way around the world."


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "First Estimates Developed Of Lightning-Associated "Sprites" -- Radio Signals Help Scientists Estimate How Many Occur In Thunderstorms." ScienceDaily. ScienceDaily, 2 April 1999. <www.sciencedaily.com/releases/1999/04/990402074416.htm>.
National Science Foundation. (1999, April 2). First Estimates Developed Of Lightning-Associated "Sprites" -- Radio Signals Help Scientists Estimate How Many Occur In Thunderstorms. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/1999/04/990402074416.htm
National Science Foundation. "First Estimates Developed Of Lightning-Associated "Sprites" -- Radio Signals Help Scientists Estimate How Many Occur In Thunderstorms." ScienceDaily. www.sciencedaily.com/releases/1999/04/990402074416.htm (accessed July 24, 2014).

Share This




More Earth & Climate News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
Powered by NewsLook.com
Storm Kills Three, Injures 20 at Virginia Campground

Storm Kills Three, Injures 20 at Virginia Campground

Reuters - US Online Video (July 24, 2014) A likely tornado tears through an eastern Virginia campground, killing three and injuring at least 20. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins