Featured Research

from universities, journals, and other organizations

Breathing Cycles In Earth's Upper Atmosphere Tied To Solar Wind Disturbances

Date:
December 20, 2008
Source:
University of Colorado at Boulder
Summary:
A new study shows the periodic "breathing" of Earth's upper atmosphere that has long puzzled scientists is due in part to cyclic solar wind disturbances, a finding that should help engineers track satellites more accurately and improve forecasts for electronic communication disruptions.

A team led by CU-Boulder used data from the German CHAMP satellite, above, to monitor changes in the upper atmosphere that affect satellite orbits, space debris and satellite communication.
Credit: NASA

A new University of Colorado at Boulder study shows the periodic "breathing" of Earth's upper atmosphere that has long puzzled scientists is due in part to cyclic solar wind disturbances, a finding that should help engineers track satellites more accurately and improve forecasts for electronic communication disruptions.

Aerospace engineering sciences department Associate Professor Jeff Thayer said the outer, gaseous shell of the atmosphere, known as the thermosphere, is known to expand and contract as it exchanges energy with the space environment, causing changes in thermosphere density. Changes in thermosphere density can alter the atmospheric drag of satellites, causing them to deviate from their predicted paths and complicating tracking and orbital adjustment maneuvers, he said.

While extreme ultraviolet radiation from the sun is the dominant mechanism that causes the thermosphere to "breathe," the new CU-Boulder study indicates high-speed wind from the sun triggers independent breathing episodes by creating geomagnetic disturbances, heating the thermosphere and altering its density. The wind streams are generated by relatively cool pockets on the sun's surface known as solar coronal holes that periodically rotate around the sun's surface, said Thayer.

"We were surprised to find the density changes were so consistent in our observations," said Thayer, lead study author. "Because of the huge increase in satellite activity in recent years, finding this new thermosphere breathing mechanism should help improve our models and increase the accuracy satellite tracking and collision avoidance."

A paper on the subject was presented at the Fall Meeting of the American Geophysical Union held Dec. 15 to Dec. 19 in San Francisco. Co-authors included Research Associate Jiuhou Lei, Professor Jeffrey Forbes, Research Associate Eric Sutton and Professor Steve Nerem of CU-Boulder's aerospace engineering sciences department.

The thermosphere begins at about 60 miles above Earth and extends to about 300 miles in altitude. The thermosphere gas is known to expand and contract on a 27-day solar rotation period due to changes in extreme UV radiation, said Thayer. The new findings indicate the thermosphere also has periodic oscillations occur at four-to-five days, six-to-seven days and nine-to-11 days caused by the violent effect of the high-speed soar winds interacting with Earth and transferring energy through auroras and enhanced electric currents.

The team used data from the German Challenging Minisatellite Payload, or CHAMP, and the NASA Advanced composition Explorer satellite to measure the solar wind properties, The research was funded by a five-year, $7 million grant from the U.S. Air Force Office of Scientific Research to a CU-Boulder aerospace engineering science group led by Forbes.

In addition to helping monitor density changes in the thermosphere, the new findings should help researchers track the growing amount of space debris in the upper atmosphere that can damage satellites and threaten astronauts, said Thayer. Last year a ground-based Chinese missile was used to intentionally destroy an aging Chinese meteorological satellite, creating thousands of chunks of debris in low-Earth orbit, a region heavily used by spacecraft, including the International Space Station.

A better understanding of the characteristics of the thermosphere should also help scientists and engineers adjust radio communications and GPS signals during periods of significant solar wind activity, he said.


Story Source:

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


Cite This Page:

University of Colorado at Boulder. "Breathing Cycles In Earth's Upper Atmosphere Tied To Solar Wind Disturbances." ScienceDaily. ScienceDaily, 20 December 2008. <www.sciencedaily.com/releases/2008/12/081215184317.htm>.
University of Colorado at Boulder. (2008, December 20). Breathing Cycles In Earth's Upper Atmosphere Tied To Solar Wind Disturbances. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2008/12/081215184317.htm
University of Colorado at Boulder. "Breathing Cycles In Earth's Upper Atmosphere Tied To Solar Wind Disturbances." ScienceDaily. www.sciencedaily.com/releases/2008/12/081215184317.htm (accessed October 2, 2014).

Share This



More Earth & Climate News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dolphins and Turtles Under Threat in Pakistan

Dolphins and Turtles Under Threat in Pakistan

AFP (Oct. 2, 2014) — The turtles and Dolphins of Pakistan's Indus river - both protected by law - are in a fight for their survival as man's activities threatens their futures. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Volcano Rescue Video Released

Raw: Japan Volcano Rescue Video Released

AP (Oct. 2, 2014) — The Tokyo Fire Department released video of rescue efforts following Saturday's eruption of Mount Ontake in central Japan. It shows firefighters and military troops carrying injured people as plumes of smoke pour from the volcano behind them. (Oct. 2) Video provided by AP
Powered by NewsLook.com
Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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