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How Can a Negative Magnetic Helicity Active Region Generate a Positive Helicity Magnetic Cloud?
(Springer, 2009-11-13)
The geoeffective magnetic cloud (MC) of 20 November 2003 was associated with the 18 November 2003 solar active events in previous studies. In some of these, it was estimated that the magnetic helicity carried by the MC had ...
Observations of magnetic helicity
(Elsevier, 2003-12)
The first observational signature of magnetic helicity in the solar atmosphere (sunspot whirls) was discovered 77 years ago. Since then, the existence of a cycle-invariant hemispheric helicity pattern has been firmly ...
Magnetic helicity budget of solar active regions from the photosphere to magnetic clouds
(Springer, 2004-12)
We have analyzed the long-term evolution of two active regions (ARs) from their emergence through their decay using observations from several instruments on board SoHO (MDI, EIT and LASCO) and Yohkoh/SXT. We have computed ...
Magnetic Flux and Helicity of Magnetic Clouds
(Springer, 2016-01)
Magnetic clouds (MCs) are formed by flux ropes (FRs) launched from the Sun as part of coronal mass ejections (CMEs). They carry away a large amount of magnetic flux and helicity. The main aim of this study is to quantify ...
Primordial magnetic helicity from stochastic electric currents
(American Physical Society, 2014-04)
We study the possibility that primordial magnetic fields generated in the transition between inflation and reheating posses magnetic helicity, HM. The fields are induced by stochastic currents of scalar charged particles ...
Properties of Magnetic tongues over a Solar Cycle
(Springer, 2016-05)
The photospheric spatial distribution of the main magnetic polarities of bipolar
active regions (ARs) present during their emergence deformations are known as magnetic tongues. They are attributed to the presence of twist ...
The Magnetic Helicity Injected by Shearing Motions
(Springer, 2002)
The Magnetic Helicity Budget of a CME-Prolific Active Region
(Springer, 2002-07)
Coronal mass ejections (CMEs) are thought to be the way by which the solar corona expels accumulated magnetic helicity which is injected into the corona via several methods. DeVore (2000) suggests that a significant quantity ...
What is the source of the magnetic helicity shed by CMEs? The long-term helicity budget of AR 7978
(EDP Sciences, 2002-02)
An isolated active region (AR) was observed on the Sun during seven rotations, starting from its birth in July 1996 to its full dispersion in December 1996. We analyse the long-term budget of the AR relative magnetic ...
Model-independent large-scale magnetohydrodynamic quantities in magnetic clouds
(Elsevier, 2005-12)
Magnetic clouds are the interplanetary manifestation of coronal mass ejections, which are transient expulsions of major quantities of magnetized plasma, from the Sun toward the heliosphere. The magnetic flux and helicity ...