Featured Research

from universities, journals, and other organizations

Auroras In Northern And Southern Hemispheres Are Not Identical

Date:
July 24, 2009
Source:
University of Bergen
Summary:
Researchers present evidence that the auroras in the Northern and the Southern hemispheres can be totally asymmetric. These findings contradict the commonly made assumption of aurora being mirror images of each other.

Asymmetric aurora.
Credit: Polar VIS Earth (J. B. Sigwarth) and IMAGE WIC (S. B. Mende)

Norwegian researchers have shown that the auroras in the Northern and the Southern hemispheres can be totally asymmetric. These findings contradict the commonly made assumption of aurora being mirror images of each other.

The study was performed by PhD student Karl Magnus Laundal and professor Nikolai Østgaard at the Institute of Physics and Technology at the University of Bergen.

"The aurora is produced due to collisions between the Earth’s atmosphere and electrically charged particles streaming along the Earth’s geomagnetic field lines. – Since these processes occur above the two hemispheres, both the Northern and the Southern light are created. So far researchers have assumed that these auroras are mirror images of each other, but our findings show that this is not always the case," professor Nikolai Østgaard says.

The researchers at the University of Bergen have used data from the two NASA-satellites IMAGE and Polar to examine the Northern and the Southern light. In the Nature letter they present several possible explanations to the unexpected result.

"The most plausible explanation involves electrical currents along the magnetic field lines. Differences in the solar exposure may lead to currents between the two hemispheres, explaining why the Northern and the Southern light are not identical," PhD student Karl Magnus Laundal says.

In addition to yielding new knowledge about the aurora, the results are important for other researchers studying the near-Earth space.

"Our study shows that data from only one hemisphere is not sufficient to state the conditions on the other hemisphere. This is important because most of our knowledge about the aurora, as well as processes in the upper atmosphere in the polar regions, is based solely on data from the Northern hemisphere," Østgaard points out.

The work of Østgaard and Laundal has been financed by the Research Council of Norway via the International Polar Year project IPY-ICESTAR.

Laundal, K.M. and Østgaard, N., Asymmetric auroral intensities in the Earth's Northern and Southern hemispheres, Nature 460, 491-493 (23 July 2009) | doi:10.1038/nature08154


Story Source:

The above story is based on materials provided by University of Bergen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Laundal et al. Asymmetric auroral intensities in the Earth's Northern and Southern hemispheres. Nature, 2009; 460 (7254): 491 DOI: 10.1038/nature08154

Cite This Page:

University of Bergen. "Auroras In Northern And Southern Hemispheres Are Not Identical." ScienceDaily. ScienceDaily, 24 July 2009. <www.sciencedaily.com/releases/2009/07/090723081756.htm>.
University of Bergen. (2009, July 24). Auroras In Northern And Southern Hemispheres Are Not Identical. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2009/07/090723081756.htm
University of Bergen. "Auroras In Northern And Southern Hemispheres Are Not Identical." ScienceDaily. www.sciencedaily.com/releases/2009/07/090723081756.htm (accessed August 30, 2014).

Share This




More Earth & Climate News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Volcano Erupts on Papua New Guinea

Raw: Volcano Erupts on Papua New Guinea

AP (Aug. 29, 2014) — Several communities were evacuated and some international flights were diverted on Friday after one of the most active volcanos in the region erupts. (Aug. 29) Video provided by AP
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Scientists Have Figured Out Why Rocks Move In Death Valley

Scientists Have Figured Out Why Rocks Move In Death Valley

Newsy (Aug. 28, 2014) — The mystery of the moving rocks in Death Valley, California, has finally been solved. Scientists are pointing to a combo of water, ice and wind. Video provided by Newsy
Powered by NewsLook.com
Big Waves, Minor Flooding from Hurricane

Big Waves, Minor Flooding from Hurricane

AP (Aug. 27, 2014) — Thundering surf spawned by Hurricane Marie pounded the Southern California coast Wednesday, causing minor flooding in a low-lying beach town. High surf warnings were posted for Los Angeles County south through Orange County. (Aug. 27) 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