* Astronomy

Members Login
Post Info TOPIC: Solar magnetic field reversal


L

Posts: 131298
Date:
Solar Magnetic Fields
Permalink  
 


Title: History of Solar Magnetic Fields since George Ellery Hale
Author: Jan Stenflo

As my own work on the Sun's magnetic field started exactly 50 years ago at Crimea in the USSR, I have been a participant in the field during nearly half the time span since Hale's discovery in 1908 of magnetic fields in sunspots. The present historical account is accompanied by photos from my personal slide collection, which show a number of the leading personalities who advanced the field in different areas: measurement techniques, from photographic to photoelectric and imaging methods in spectro-polarimetry; theoretical foundations of MHD and the origin of cosmic magnetic fields (birth of dynamo theory); the quest for increased angular resolution from national projects to international consortia (for instruments both on ground and in space); introduction of the Hanle effect in astrophysics and the Second Solar Spectrum as its playground; small-scale nature of the field, the fundamental resolution limit, and transcending it by resolution-independent diagnostics.

Read more (1123kb, PDF)



__________________


L

Posts: 131298
Date:
Solar magnetic field
Permalink  
 


The origin of the magnetic field covering the Sun has been discovered

The magnetic field that covers the Sun and determines its behaviour - the eleven year cycles no less than such conspicuous phenomena as solar spots and solar storms - also has another side to it: a magnetic web that covers the entire surface of the Sun at rest and whose net magnetic flow is greater than that of the active areas. A study led by the Institute of Astrophysics of Andalusia (IAA-CSIC) has revealed where the flow that feeds this web comes from.
Read more



__________________


L

Posts: 131298
Date:
RE: Solar magnetic field reversal
Permalink  
 


The Sun's Magnetic Field is about to Flip

Something big is about to happen on the sun. According to measurements from NASA-supported observatories, the sun's vast magnetic field is about to flip.



__________________


L

Posts: 131298
Date:
Permalink  
 

ScienceCasts: The Sun's Magnetic Field is About to Flip

Spoiler



__________________


L

Posts: 131298
Date:
Solar magnetic field
Permalink  
 


Researchers reveal model of Sun's magnetic field

Researchers at the Universities of Leeds and Chicago have uncovered an important mechanism behind the generation of astrophysical magnetic fields such as that of the Sun.
Scientists have known since the 18th Century that the Sun regularly oscillates between periods of high and low solar activity in an 11-year cycle, but have been unable to fully explain how this cycle is generated.

Read more



__________________


L

Posts: 131298
Date:
Solar magnetic field reversal
Permalink  
 


Title: Reversals of the solar dipole
Authors: David Moss, Leonid L. Kitchatinov, Dmitri Sokoloff

During a solar magnetic field reversal the magnetic dipole moment does not vanish, but migrates between poles, in contradiction to the predictions of mean-field dynamo theory. We try to explain this as a consequence of magnetic fluctuations. We exploit the statistics of fluctuations to estimate observable signatures. Simple statistical estimates, taken with results from mean-field dynamo theory, suggest that a non-zero dipole moment may persist through a global field reversal. Fluctuations in the solar magnetic field may play a key role in explaining reversals of the dipolar component of the field.

Read more (17kb, PDF)



__________________
Page 1 of 1  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard