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:6/23/2017)... and ITHACA, N.Y. , June 23, ... University, a leader in dairy research, today announced a ... to help reduce the chances that the global milk ... of this dairy project, Cornell University has become the ... the Food Supply Chain, a food safety initiative that ...
(Date:5/23/2017)... May 23, 2017  Hunova, the first robotic gym for the rehabilitation ... officially launched in Genoa, Italy . The first 30 ... and the USA . The technology was developed and ... by the IIT spin-off Movendo Technology thanks to a 10 million euro ... Release, please click: ...
(Date:5/16/2017)... May 16, 2017   Bridge Patient Portal ... and MD EMR Systems , an electronic ... for GE, have established a partnership to build ... and the GE Centricity™ products, including Centricity Practice ... These new integrations will allow healthcare ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... Proscia ... be hosting a Webinar titled, “Pathology is going digital. Is your lab ready?” ... pathology adoption best practices and how Proscia improves lab economics and realizes an ...
(Date:10/11/2017)... Austin, TX (PRWEB) , ... October 11, 2017 ... ... in August compared the implantation and pregnancy rates in frozen and fresh ... the contribution of progesterone and maternal age to IVF success. , After comparing ...
(Date:10/10/2017)... ... 10, 2017 , ... For the second time in three ... Mentoring Award. Representatives of the FirstHand program travelled to Washington, D.C. Tuesday, October ... US2020’s mission is to change the trajectory of STEM education in America by ...
(Date:10/10/2017)... CALIFORNIA (PRWEB) , ... October 10, 2017 , ... ... technological innovation and business process optimization firm for the life sciences and healthcare ... BoxWorks conference in San Francisco. , The presentation, “Automating GxP Validation for ...
Breaking Biology Technology: