Navigation Links
Hinode: new insights on the origin of solar wind
Date:12/7/2007

Spectacular images and data from the Hinode mission have shed new light on the Sun's magnetic field and the origins of solar wind, which can disrupt power grids, satellites and communications on Earth.

The results are published in the 7 December issue of the journal Science.

Data from Hinode, a Japanese (JAXA) mission with ESA participation, shows that magnetic waves play a critical role in driving the solar wind into space. The solar wind is a stream of electrically charged gas that is propelled away from the Sun in all directions at speeds of almost 1.5 million km/h. Better understanding of the solar wind may lead to more accurate prediction of damaging radiation waves before they reach satellites.

How the solar wind is formed and powered has been the subject of debate for decades. Powerful magnetic waves in the electrically charged gas near the Sun (called Alfvn waves) have always been a leading-candidate force in the formation of solar wind. In principle, such waves can transfer energy from the Sun's surface up through its atmosphere, or corona, into the solar wind.

In the solar atmosphere, Alfvn waves are created when convective motions and sound waves push magnetic fields around, or when dynamic processes create electrical currents that allow the magnetic fields to change shape or reconnect.

"Until now, Alfvn waves have been impossible to observe because of limited resolution of available instruments," said Alexei Pevtsov, Hinode program scientist, at NASA Headquarters, Washington, USA. "With the help of Hinode, we are now able to see direct evidence of Alfvn waves, which will help us unravel the mystery of how the solar wind is powered."

Using Hinode's high resolution X-ray telescope, a team led by Jonathan Cirtain, a solar physicist at NASA's Marshall Space Flight Center, Alabama, USA, was able to peer low into the corona at the Sun's poles and observe record numbers of X-ray jets. The jets are fountains of rapidly moving hot plasma. Previous research detected only a few jets daily.

With Hinode's higher sensitivity, Cirtain's team observed an average of 240 jets per day. They conclude that magnetic reconnection, a process where two oppositely charged magnetic fields collide and release energy, is frequently occurring in the low solar corona. This interaction forms both Alfvn waves and the burst of energized plasma in X-ray jets.

"These observations show a clear relationship between magnetic reconnection and Alfvn wave formation in the X-ray jets." said Cirtain. "The large number of jets, coupled with the high speeds of the outflowing plasma, lends further credence to the idea that X-ray jets are a driving force in the creation of the fast solar wind."

Another research team led by Bart De Pontieu, a solar physicist at Lockheed Martin's Solar and Astrophysics Laboratory, California, USA, focused on the Sun's chromosphere, the region sandwiched between the solar surface and its corona. Using extremely high-resolution images from Hinode's Solar Optical Telescope, De Pontieu's team found that the chromosphere is riddled with Alfvn waves. When the waves leak into the corona, they are strong enough to power the solar wind.

"We find that most of these Alfvn waves have periods of several minutes, much longer than many theoretical models have assumed in the past," says De Pontieu. Comparisons with advanced computer simulations from the University of Oslo, Norway, indicate that reconnection is not the only source of the Alfvn waves. "The simulations imply that many of the waves occur when the Sun's magnetic field is jostled around by convective motions and sound waves in the low atmosphere," continued De Pontieu.


'/>"/>

Contact: Bernhard Fleck
bfleck@esa.nascom.nasa.gov
301-286-4098
European Space Agency  
Source:Eurekalert

Related biology news :

1. Stomach stem cell discovery could bring cancer insights
2. KGI professor contributes new insights on jumping genes
3. Study involving more than 100 scientists provides new insights on green algae
4. New insights into how lasers cut flesh
5. Tumor genome analysis unveils new insights into lung cancer
6. New insights into the fate of antiparasitics in manure and manured soils
7. Comet probes reveal evidence of origin of life, scientists claim
8. Good earth: Brown chemists show origin of soil-scented geosmin
9. Georgia Tech/Emory Center to study origin of life
10. Venous origin of the mammalian lymphatic vasculature
11. St. Jude settles century-old debate on origin of mammalian network of lymphatic vessels
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Hinode: new insights on the origin of solar wind
(Date:5/12/2016)... DALLAS , May 12, 2016 ... has just published the overview results from the Q1 ... of the recent wave was consumers, receptivity to a ... wearables data with a health insurance company. ... choose to share," says Michael LaColla , CEO ...
(Date:4/28/2016)... First quarter 2016:   , ... the first quarter of 2015 The gross margin was ... 18.8) and the operating margin was 40% (-13) Earnings ... flow from operations was SEK 249.9 M (21.2) , ... SEK 7,000-8,500 M. The operating margin for 2016 is ...
(Date:4/15/2016)... CHICAGO , April 15, 2016  A ... companies make more accurate underwriting decisions in a ... offering timely, competitively priced and high-value life insurance ... health screenings. With Force Diagnostics, rapid ... and lifestyle data readings (blood pressure, weight, pulse, ...
Breaking Biology News(10 mins):
(Date:5/25/2016)... ... May 25, 2016 , ... Biohaven Pharmaceutical Holding Company ... granted the company’s orphan drug designation request covering BHV-4157 for the treatment of ... the FDA. , Spinocerebellar ataxia is a rare, debilitating neurodegenerative disorder that ...
(Date:5/24/2016)... (PRWEB) , ... May 24, 2016 , ... Last week, ... for corporate executives and entrepreneurs, held The Future of San Diego Life Science event ... San Diego life science community attended the event with speakers Dr. Rich Heyman, former ...
(Date:5/23/2016)... Ohio (PRWEB) , ... May 23, 2016 , ... ... Trends That Will Drive Precision Farming in 2017 and Beyond. The paper outlines ... practitioners in the precision ag industry. , “We’ve witnessed a lot of highs ...
(Date:5/23/2016)... LONDON , May 23, 2016 - ... by 40% - Frontage Implement a Single Platform to ... Compliance and Traceability Within the Bioanalytical lab Frontage Laboratories, ... the United States and China , ... its laboratory facilities. In addition to serving as the global electronic ...
Breaking Biology Technology: