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Related papers: Coronal Hole Detection and Open Magnetic Flux

200 papers

In this review, our present day understanding of the Sun's global photospheric and coronal magnetic fields is discussed from both observational and theoretical viewpoints. Firstly, the large-scale properties of photospheric magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-06-12 D. H. Mackay , A. R. Yeates

At low coronal temperatures around or below 1 MK distinct areas in the surroundings of active regions (AR) show emission at a level significantly below the emission coming from the quiet Sun (QS). These areas are referred to as dark halos,…

Solar and Stellar Astrophysics · Physics 2026-05-13 J. D. Nölke , S. K. Solanki , J. Hirzberger , H. Peter , L. P. Chitta , K. H. Glassmeier , D. Calchetti , G. Valori

According to CACTus catalog, during periods of a high solar activity every day up to tens of coronal mass ejections are observed. Such ejections have an impact on the flux of cosmic rays that permeate the space around us. Unlike most ground…

High Energy Astrophysical Phenomena · Physics 2017-01-03 I. I. Astapov , N. S. Barbashina , V. V. Borog , I. S. Veselovsky , N. V. Osetrova , A. A. Petrukhin , V. V. Shutenko

We study the relationship between full-disk solar radiative flux at different wavelengths and average solar photospheric magnetic-flux density, using daily measurements from the Kitt Peak magnetograph and other instruments extending over…

Solar and Stellar Astrophysics · Physics 2010-06-23 Dora Preminger , Dibyendu Nandy , Gary Chapman , Petrus C. H. Martens

In recent years, a two-dimensional (2D) coronal seismology technique applied to spectral-imaging data from the Coronal Multi-channel Polarimeter (CoMP) and UCoMP has enabled routine measurement of the global coronal magnetic field. The…

Solar and Stellar Astrophysics · Physics 2026-01-16 Zihao Yang , Sarah Gibson , Matthias Rempel , Giuliana de Toma

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…

Solar and Stellar Astrophysics · Physics 2020-11-05 Zihao Yang , Hui Tian , Steven Tomczyk , Richard Morton , Xianyong Bai , Tanmoy Samanta , Yajie Chen

Coronal loops, seen in solar coronal images, are believed to represent emission from magnetic flux tubes with compact cross-sections. We examine the 3D structure of plasma above an active region in a radiative magnetohydrodynamic simulation…

Solar and Stellar Astrophysics · Physics 2022-03-09 A. Malanushenko , M. C. M. Cheung , C. E. DeForest , J. A. Klimchuk , M. Rempel

We have measured the root-mean-square (RMS) amplitude of intensity fluctuations, $\Delta I$, in plume and interplume regions of a polar coronal hole. These intensity fluctuations correspond to density fluctuations. Using data from the…

Solar and Stellar Astrophysics · Physics 2018-06-27 Michael Hahn , Elke D'Huys , Daniel Wolf Savin

In the era of space exploration, the implications of space weather have become increasingly evident. Central to this is the phenomenon of coronal holes, which can significantly influence the functioning of satellites and aircraft. These…

Solar and Stellar Astrophysics · Physics 2024-06-24 Juyoung Yun

We developed an automated procedure for the identification of transient brightenings in images from the X-ray telescope on-board Hinode taken with an Al Poly filter in the equatorial coronal holes, polar coronal holes, and the quiet Sun…

Solar and Stellar Astrophysics · Physics 2015-05-18 S. Subramanian , M. S. Madjarska , J. G. Doyle

Coronal loops reveal crucial information about the nature of both coronal magnetic fields and coronal heating. The shape of the corresponding flux tube cross section and how it varies with position are especially important properties. They…

Solar and Stellar Astrophysics · Physics 2020-07-31 James A. Klimchuk , Craig E. DeForest

It is widely believed that loops observed in the solar atmosphere trace out magnetic field lines. However, the degree to which magnetic field extrapolations yield field lines that actually do follow loops has yet to be studied…

Solar and Stellar Astrophysics · Physics 2018-06-27 Harry P. Warren , Nicholas A. Crump , Ignacio Ugarte-Urra , Xudong Sun , Markus J. Aschwanden , Thomas Wiegelmann

A method of synoptic map assimilation has been developed to study global rearrangements of open magnetic flux and formation of polar coronal holes (PCHs) in the current cycle. The analysis reveals ensembles of coronal holes (ECHs) which…

Solar and Stellar Astrophysics · Physics 2017-11-08 E. M. Golubeva , A. V. Mordvinov

We use full-disk, SOHO/EIT 195 $\AA$ calibrated images to measure latitudinal and day to day variations of area and average photon fluxes of the near equatorial coronal holes. In addition, energy emitted by the coronal holes with their…

Solar and Stellar Astrophysics · Physics 2022-04-12 K. M. Hiremath , Manjunath Hegde

The heating of the solar chromosphere and corona to the observed high temperatures, imply the presence of ongoing heating that balances the strong radiative and thermal conduction losses expected in the solar atmosphere. It has been…

The understanding of the solar magnetic coronal structure is tightly linked to the shape of open field regions, specifically coronal holes. A dynamically evolving coronal hole coincides with the local restructuring of open to closed…

We recently proposed a method to calculate the relative magnetic helicity in a finite volume for a given magnetic field which however required the flux to be balanced separately on all the sides of the considered volume. In order to allow…

Solar and Stellar Astrophysics · Physics 2018-05-30 Shangbin Yang , Joerg Buechner , Jan Skala , Hongqi Zhang

Cosmic ray muons have emerged as a non-conventional high-energy radiation probe to monitor dense and large objects. Muons are the most abundant cosmic radiation on Earth, however, their flux at sea level is approximately 10,000 min^-1m^-2…

Instrumentation and Methods for Astrophysics · Physics 2022-01-05 Junghyun Bae , Stylianos Chatzidakis

We present a novel investigation into the relationship between simple estimates of magnetic flux balance and the Ne VIII Doppler velocity partitioning of a large equatorial coronal hole observed by the Solar Ultraviolet Measurements of…

Astrophysics · Physics 2007-05-23 Scott W. McIntosh , Alisdair R. Davey , Scott W. McIntosh

Context: One aspect of understanding the dynamics of the quiet Sun is to quantify the evolution of the flux within small-scale magnetic features. These features are routinely observed in the quiet photosphere and were given various names,…

Solar and Stellar Astrophysics · Physics 2015-02-04 R. Attie , D. E. Innes