相关论文: Helical surface structures

We develop a two-scale formalism to determine global magnetic helicity spectra in systems where the local magnetic helicity has opposite signs on both sides of the equator, giving rise to cancelation with conventional methods. We verify…

The large-scale field of the Sun is well represented by its lowest energy (or potential) state. Recent observations, by comparison, reveal that many solar-type stars show large-scale surface magnetic fields that are highly non-potential -…

This paper reviews the studies of solar photospheric magnetic field evolution in active regions and its relationship to solar flares. It is divided into two topics, the magnetic structure and evolution leading to solar eruptions and the…

We present a new methodology which can determine magnetic helicity transport by the passage of helical magnetic field lines from sub-photosphere and the shuffling motions of foot-points of preexisting coronal field lines separately. It is…

Solar and stellar dynamos shed small-scale and large-scale magnetic helicity of opposite signs. However, solar wind observations and simulations have shown that some distance above the dynamo both the small-scale and large-scale magnetic…

The aim of this paper is to extend our previous study of the solar-cycle variations of the meridional flows and to investigate their latitudinal and longitudinal structure in the subphotospheric layer, especially their variations in…

In our earlier study of this series (Park et al. 2020, Paper I), we examined the hemispheric sign preference (HSP) of magnetic helicity flux $dH/dt$ across photospheric surfaces of 4802 samples of 1105 unique active regions (ARs) observed…

In the solar corona, magnetic helicity slowly and continuously accumulates in response to plasma flows tangential to the photosphere and magnetic flux emergence through it. Analyzing this transfer of magnetic helicity is key for identifying…

Magnetic helicity quantifies how globally sheared and/or twisted is the magnetic field in a volume. This quantity is believed to play a key role in solar activity due to its conservation property. Helicity is continuously injected into the…

Both in the Faraday Rotation Measure and the intrinsic polarization angle, new features are revealed to indicate a helical magnetic field operating along the jet of the bright active galactic nuclei 3C 273. The helical field has been…

Magnetic switchbacks are large amplitude deflections of the magnetic field within the solar wind. They are Alfv\'enic in character and so are associated with a spike in velocity and a generally small variation in local plasma density. Early…

This work examines the relationship between solar eruptivity and the relative helicity that is contained around the polarity inversion line (PIL) of the magnetic field, along with its current-carrying component. To this end, we analyze the…

Maps of the magnetic field at the Sun's surface are commonly used as boundary conditions in space-weather modeling. However, continuous observations are only available from the Sun's Earth-facing side. One commonly used approach to mitigate…

Solar eruptive events such as flares and coronal mass ejection (CME)-driven shocks can release solar energetic particles (SEPs) into the heliosphere. The heliospheric current sheet (HCS) is a large-scale structure that separates regions of…

Magnetic fields on a range of scales play a large role in the ecosystems of galaxies, both in the galactic disk and in the extended layers of gas away from the plane. Observing magnetic field strength, structure and orientation is complex,…

Variations of the azimuthal magnetic fields of the Sun in the 23-25 activity cycles of the activity cycles are considered. To identify azimuthal magnetic fields, the analysis of daily observations of LOS magnetic fields from the regions…

Among many other measurable quantities the summer of 2009 saw a considerable low in the radiative output of the Sun that was temporally coincident with the largest cosmic ray flux ever measured at 1AU. A hemispheric asymmetry in magnetic…

Large scale dynamo-generated fields are a combination of interlocked poloidal and toroidal fields. Such fields possess magnetic helicity that needs to be regenerated and destroyed during each cycle. A number of numerical experiments now…

Solar filaments are spectacular objects in the solar atmosphere, consisting of accumulations of cool, dense, and partially ionized plasma suspended in the hot solar corona against gravity. The magnetic structures that support the filament…

Magnetic clouds (MCs) are formed by flux ropes (FRs) launched from the Sun as part of coronal mass ejections (CMEs). They carry away an important amount of magnetic flux and helicity. The main aim of this study is to quantify these…