Low-frequency radio emissions from high-altitude sprite discharge

Dec 18, 2012

When lightning strikes from a towering cumulonimbus cloud down to the ground, the electrical discharge can perturb the atmosphere's electric field, potentially triggering a second event-sprite discharge. This more elusive type of electrical discharge, which produces lightning that is red in color, initiates from high altitudes, with streamers propagating down toward the top of the cumulonimbus cloud.

Coincident with the dramatic displays, researchers have previously identified low-frequency , which they suggest may be produced in association with the sprite discharge. Investigating this hypothesis, Qin et al. used a two-dimensional plasma model to calculate the radio emissions that should be produced by a single sprite streamer.

The authors find the frequency of the radio emissions that should be produced by a sprite streamer depends on two main factors: the (which decreases with altitude) and the background electric field through which the streamer is propagating. The authors find that sprite streamers that initiate from 75 kilometers (47 miles) altitude emit with frequencies from 0 to 3 kilohertz (up to the "very low frequency" range).

If the sprite streamers spawned at 40 kilometers (25 miles) altitude, they would emit low-frequency radiowaves, with frequencies up to 300 kilohertz. Further, the authors suggest that the sprite streamers branching mechanism could act as a band-pass filter, with the radio wave frequencies being lower at high altitudes than at low altitudes.

Explore further: Sea-level surge at Antarctica linked to icesheet loss

More information: Low frequency electromagnetic radiation from sprite streamers, Geophysical Research Letters, doi:10.1029/2012GL053991, 2012

add to favorites email to friend print save as pdf

Related Stories

NASA seeing sprites (w/ Video)

Aug 14, 2012

High above the clouds during thunderstorms, some 50 miles above Earth a different kind of lightning dances. Bursts of red and blue light, known as "sprites," flash for a scant one thousandth of a second. ...

Soft drink could enhance effects of an anti-cancer drug

Oct 13, 2010

Experiments with an artificial stomach suggest that a popular lemon-lime soft drink could play an unexpected role in improving the effectiveness of an oral anticancer drug. The experiments produced evidence that patients ...

Cassini Sees Lightening on Saturn

Apr 14, 2010

(PhysOrg.com) -- NASA's Cassini spacecraft has captured images of lightning on Saturn. The images have allowed scientists to create the first movie showing lightning flashing on another planet.

Earth, Venus lightnings produced by similar mechanisms

Sep 27, 2010

Despite the great differences between the atmospheres of Venus and Earth, scientists have discovered that very similar mechanisms produce lightning on the two planets. The rates of discharge, the intensity ...

Another M-class flare from Sunspot 1515

Jul 05, 2012

Active Region 1515 has now spit out 12 M-class flares since July 3. Early in the morning of July 5, 2012 there was an M6.1 flare. It peaked at 7:44 AM EDT. This caused a moderate – classified as R2 on ...

Recommended for you

Aging Africa

Aug 29, 2014

In the September issue of GSA Today, Paul Bierman of the University of Vermont–Burlington and colleagues present a cosmogenic view of erosion, relief generation, and the age of faulting in southernmost Africa ...

NASA animation shows Hurricane Marie winding down

Aug 29, 2014

NOAA's GOES-West satellite keeps a continuous eye on the Eastern Pacific and has been covering Hurricane Marie since birth. NASA's GOES Project uses NOAA data and creates animations and did so to show the end of Hurricane ...

EU project sails off to study Arctic sea ice

Aug 29, 2014

A one-of-a-kind scientific expedition is currently heading to the Arctic, aboard the South Korean icebreaker Araon. This joint initiative of the US and Korea will measure atmospheric, sea ice and ocean properties with technology ...

User comments : 0