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Related papers: Coronal Hole Detection and Open Magnetic Flux

200 papers

The open solar flux, that is, the total magnetic flux escaping the Sun, is one of the most important parameters connecting solar activity to the Earth. The open solar flux is commonly estimated from photospheric magnetic field measurements…

Solar and Stellar Astrophysics · Physics 2024-08-23 Ismo Tähtinen , Timo Asikainen , Kalevi Mursula

Optical observations of solar corona provide key information on its magnetic geometry. The large-scale open field of the corona plays an important role in shaping the ambient solar wind and constraining the propagation dynamics of the…

Solar and Stellar Astrophysics · Physics 2025-06-19 Vadim M. Uritsky , Christopher E. Rura , Cooper Downs , Shaela I. Jones , Charles Nickolos Arge , Nathalia Alzate

It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…

Solar and Stellar Astrophysics · Physics 2022-11-02 James A. Klimchuk , Kalman J. Knizhnik , Vadim M. Uritsky

Hot channels (HCs), high temperature erupting structures in the lower corona of the Sun, have been proposed as a proxy of magnetic flux ropes (MFRs) since their initial discovery. However, it is difficult to make definitive proof given the…

Solar and Stellar Astrophysics · Physics 2015-08-06 Hongqiang Song , Yao Chen , Jie Zhang , Xin Cheng , Bing Wang , Qiang Hu , Gang Li , Yuming Wang

The distribution and evolution of the magnetic field at the solar poles through a solar cycle is an important parameter in understanding the solar dynamo. The accurate observations of the polar magnetic flux is very challenging from the…

Solar and Stellar Astrophysics · Physics 2024-07-26 Sanjay Gosain , Han Uitenbroek

Coronal dimmings, localized regions of reduced emission in the EUV and soft X-rays, are interpreted as density depletions due to mass loss during the CME expansion. They contain crucial information on the early evolution of CMEs low in the…

Solar and Stellar Astrophysics · Physics 2018-08-29 Karin Dissauer , Astrid M. Veronig , Manuela Temmer , Tatiana Podladchikova , Kamalam Vanninathan

The adopted WSA model embedded in EUHFORIA (EUropean Heliospheric FORecasting Information Asset) is compared to EUV observations. According to the standard paradigm coronal holes are sources of open flux thus we use remote sensing EUV…

Solar and Stellar Astrophysics · Physics 2020-01-08 Eleanna Asvestari , Stephan G. Heinemann , Mannuela Temmer , Jens Pomoell , Emilia Kilpua , Jasmina Magdalenic , Stefaan Poedts

In this ISSI-supported series of studies on magnetic helicity in the Sun, we systematically implement different magnetic helicity calculation methods on high-quality solar magnetogram observations. We apply finite-volume, discrete flux tube…

Solar and Stellar Astrophysics · Physics 2021-11-24 J. K. Thalmann , M. K. Georgoulis , Y. Liu , E. Pariat , G. Valori , S. Anfinogentov , F. Chen , Y. Guo , K. Moraitis , S. Yang , A. Mastrano

Coronal holes are recognized as the primary sources of heliospheric open magnetic flux (OMF). However, a noticeable gap exists between in-situ measured OMF and that derived from remote sensing observations of the Sun. In this study, we…

Investigating the properties of magnetic flux emergence is one of the most important problems of solar physics. In this study we present a newly developed deep-focus time-distance measurement scheme which is able to detect strong emerging…

Solar and Stellar Astrophysics · Physics 2012-03-13 Stathis Ilonidis , Junwei Zhao , Alexander G. Kosovichev

We apply a new method to determine the magnetic field in coronal loops using observations of coronal loop oscillations. We analyze seven Doppler shift oscillation events detected by SUMER in the hot flare line Fe XIX to obtain oscillation…

Astrophysics · Physics 2008-11-26 Tongjiang Wang , Davina E. Innes , Jiong Qiu

The study of the evolution of coronal holes (CHs) is especially important in the context of high-speed solar wind streams (HSS) emanating from them. Stream interaction regions may deliver large amount of energy into the Earths system, cause…

In solar physics, it is a big challenge to measure the magnetic fields directly from observations in the upper solar atmosphere, including the chromosphere and corona. Radio observations are regarded as the most feasible approach to…

Solar and Stellar Astrophysics · Physics 2022-06-22 Baolin Tan

Current coronal mass ejection (CME) models set their lower boundary to be in the lower corona. They do not calculate accurately the transfer of free magnetic energy from the convection zone to the magnetically dominated corona because they…

Solar and Stellar Astrophysics · Physics 2015-05-19 James E. Leake , Mark G. Linton , Spiro K. Antiochos

Low and mid-latitude coronal holes (CHs) observed on the Sun during the current solar activity minimum (from September 21, 2006, Carrington rotation (CR) 2048, until June 26, 2009 (CR 2084)) were analyzed using {\it SOHO}/EIT and STEREO-A…

Solar and Stellar Astrophysics · Physics 2015-05-18 V. Abramenko , V. Yurchyshyn , J. Linker , Z. Mikic , J. Luhmann , C. Lee

A method for automated coronal hole detection using He I 1083 nm spectroheliograms and photospheric magnetograms is presented here. The unique line formation of the helium line allows for the detection of regions associated with solar…

Astrophysics · Physics 2007-05-23 C. J. Henney , J. W. Harvey

The magnetic fields in the solar polar region are important to our understanding of the internal dynamo process, the global coronal structure, and the origin of the solar wind. The inference of polar fields based on spectropolarimetric…

Solar and Stellar Astrophysics · Physics 2026-03-16 Bryan Yamashiro , Xudong Sun , Ivan Milić , Carlos Quintero Noda , Adur Pastor Yabar , Rebecca Centeno , Jiayi Liu , Milan Gošić , Kai Yang

We have performed a three-dimensional magnetohydrodynamic simulation to study the emergence of a twisted magnetic flux tube from -20,000 km of the solar convection zone to the corona through the photosphere and the chromosphere. The middle…

Solar and Stellar Astrophysics · Physics 2015-06-03 S. Toriumi , T. Yokoyama

(Abridged) Aim: We attempt to determine robust estimates of the heliospheric magnetic flux ($\Phi_H$) using Parker Solar Probe (PSP) data, analyze how susceptible this is to overestimation compared to the true open flux ($\Phi_{open}$),…

We present a new MHD wave decomposition method that overcomes the limitations of existing wave identification methods. Our method allows to investigate the energy fluxes in different MHD modes at different locations of the solar atmosphere…

Solar and Stellar Astrophysics · Physics 2022-04-20 N. Yadav , Rony Keppens , B. Popescu Braileanu