Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NCAR researcher sheds light on solar storms

31.05.2005


New research from the National Center for Atmospheric Research (NCAR) links a particular magnetic structure on the Sun with the genesis of powerful solar storms that can buffet Earth’s atmosphere. The research may enable scientists to create more accurate computer models of the solar storms, known as coronal mass ejections (CMEs), and could eventually point the way to forecasting the storms days before they occur. Sarah Gibson, a scientist at NCAR’s High Altitude Observatory (HAO), will present her findings at the American Geophysical Union conference in New Orleans on Thursday, May 26. Her invited talk is in recognition of winning this year’s Karen Harvey Prize. Awarded by the Solar Physics Division of the American Astronomical Society, the prize recognizes an early-career scientist who has produced exceptional solar research. CMEs are a focus of solar research because they suddenly and violently release billions of tons of matter and charged particles that escape from the Sun and speed through space. Ejections pointed toward Earth can set off disturbances when they reach the upper atmosphere, affecting satellites, ground-based communications systems, and power grids.



For her research, Gibson turned to a unique data set: white-light images of the lower reaches of the Sun’s enormous halo, called the corona. Taken by NCAR’s Mark-IV K-Coronameter on Mauna Loa in Hawaii, the images are sensitive to density alone, avoiding the ambiguity of most other solar images that depend on both temperature and density. The images revealed that lower-density regions in the corona consistent with twisted magnetic field lines can form prior to a CME. The twisted areas, known as magnetic flux ropes, store massive amounts of energy.

"The structures indicate a magnetic system that has enough energy to fuel a CME," Gibson explains. "But their presence is not, by itself, an indication that a CME is about to occur. For that, we need to look at additional characteristics."


The research may put to rest an important debate among solar physicists over whether magnetic flux ropes can form prior to an ejection or are merely present when an ejection takes place. Gibson’s findings suggest that, to understand the forces that create CMEs, solar scientists should use magnetic flux ropes as starting points for computer models of the massive storms.

To conduct her study, Gibson used Mark-IV images to observe dark, lower-density areas, known as cavities, that can be formed by the strong, sheared magnetic fields of magnetic flux ropes. She and NCAR colleagues analyzed 13 cavity systems from November 1999 to January 2004. Seven of these systems could be associated with CMEs, and four cavities were directly observed by the coronameter to erupt as CMEs. Gibson used a second technique to identify an additional eight CMEs that erupted from already-formed cavities. She found those cases by gathering images of CMEs and backtracking to see whether cavities existed at those CME sites before each eruption.

One of Gibson’s next steps will be to analyze cavities that result in CMEs to determine whether they have identifiable characteristics that may help scientists forecast a CME. Her preliminary findings indicate that a cavity begins to bulge and rise higher in the corona just before erupting. Cavities may also darken and become more sharply defined prior to eruption.

Gibson will also try to determine how widespread cavities are, and if it is possible that most, or even all, CMEs are preceded by the formation of magnetic flux ropes. Beginning next year, she will supplement the Mauna Loa observations with data from a pair of new NASA satellites, known as STEREO (Solar Terrestrial Relations Observatory). Instruments aboard STEREO will provide stereoscopic measurements and 24-hour coverage of the lower solar corona, significantly increasing the chances of directly observing cavities erupting into CMEs.

Anatta | EurekAlert!
Further information:
http://www.ucar.edu

More articles from Physics and Astronomy:

nachricht When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>