English
Related papers

Related papers: Helioseismology of Pre-Emerging Active Regions I: …

200 papers

The subsurface properties of active regions prior to their appearance at the solar surface may shed light on the process of active region formation. Helioseismic holography has been applied to samples taken from two populations of regions…

Solar and Stellar Astrophysics · Physics 2016-08-24 G. Barnes , A. C. Birch , K. D. Leka , D. C. Braun

Local helioseismology provides a unique opportunity to investigate the subsurface structure and dynamics of active regions and their effect on the large-scale flows and global circulation of the Sun. We use measurements of plasma flows in…

Solar and Stellar Astrophysics · Physics 2016-07-19 Alexander G. Kosovichev , Junwei Zhao , Stathis Ilonidis

A time-distance helioseismic technique, similar to the one used by Ilonidis et al (2011), is applied to two independent numerical models of subsurface sound-speed perturbations to determine the spatial resolution and accuracy of phase…

Solar and Stellar Astrophysics · Physics 2021-06-02 John T. Stefan , Alexander G. Kosovichev , Andrey M. Stejko

We report on average subsurface properties of pre-emerging active regions as compared to areas where no active region emergence was detected. Helioseismic holography is applied to samples of the two populations (pre-emergence and without…

Solar and Stellar Astrophysics · Physics 2013-03-07 A. C. Birch , D. C. Braun , K. D. Leka , G. Barnes , B. Javornik

Observations from the Solar Dynamics Observatory (SDO) have the potential for allowing the helioseismic study of the formation of hundreds of active regions, which would enable us to perform statistical analyses. Our goal is to collate a…

Solar and Stellar Astrophysics · Physics 2016-09-08 H. Schunker , D. C. Braun , A. C. Birch , R. B. Burston , L. Gizon

The goal of helioseismology is to provide accurate information about the Sun's interior from the observations of the wave field at its surface. In the last three decades, both global and local helioseismology studies have made significant…

In this dataset we provide a comprehensive collection of magnetograms (images quantifying the strength of the magnetic field) from the National Aeronautics and Space Administration's (NASA's) Solar Dynamics Observatory (SDO). The dataset…

Solar and Stellar Astrophysics · Physics 2024-02-13 Laura E. Boucheron , Ty Vincent , Jeremy A. Grajeda , Ellery Wuest

The analysis of waves in the visible side of the Sun allows the detection of active regions in the farside through local helioseismology techniques. The knowledge of the magnetism in the whole Sun, including the non-visible hemisphere, is…

Solar and Stellar Astrophysics · Physics 2019-12-04 T. Felipe , A. Asensio Ramos

Helioseismic holography is a useful method to detect active regions on the Sun's far side and improve space weather forecasts. We aim to improve helioseismic holography by using a clear formulation of the problem, an accurate forward solver…

Solar and Stellar Astrophysics · Physics 2023-01-18 Dan Yang , Laurent Gizon , Hélène Barucq

Context. Far-side helioseismology is a technique used to infer the presence of active regions in the far hemisphere of the Sun based on the interpretation of oscillations measured in the near hemisphere. A neural network has been recently…

Solar and Stellar Astrophysics · Physics 2021-08-25 E. G. Broock , T. Felipe , A. Asensio Ramos

We investigate the evolution of subsurface flows during the emergence and the active phase of sunspot regions using the time-distance helioseismology analysis of the full-disk Dopplergrams from the Helioseismic and Magnetic Imager (HMI)…

Solar and Stellar Astrophysics · Physics 2024-12-25 Alexander G. Kosovichev , Viacheslav M. Sadykov

In our previous articles (Chertok et al.: 2013, Solar Phys. 282, 175, and 2015, Solar Phys. 290, 627), we presented a preliminary tool for the early diagnostics of the geoeffectiveness of solar eruptions based on the estimate of the total…

Solar and Stellar Astrophysics · Physics 2017-04-19 I. M. Chertok , V. V. Grechnev , A. A. Abunin

Magnetic active regions on the Sun are harbingers of space weather events. Understanding the physics of how they form and evolve will improve space weather forecasting. Our aim is to characterise the surface magnetic field and flows for a…

Solar and Stellar Astrophysics · Physics 2023-12-08 Camron S. Alley , Hannah Schunker

The goal of local helioseismology is to elicit three-dimensional information about the sub-surface (or far-side) structure and dynamics of the Sun from observations of the helioseismic wave field at the surface. The physical quantities of…

Solar and Stellar Astrophysics · Physics 2015-05-19 Hannah Schunker

We present several methods towards construction of precursors, which show great promise towards early predictions, of solar flare events in this paper. A data pre-processing pipeline is built to extract useful data from multiple sources,…

Solar and Stellar Astrophysics · Physics 2020-01-08 Yang Chen , Ward B. Manchester , Alfred O. Hero , Gabor Toth , Benoit DuFumier , Tian Zhou , Xiantong Wang , Haonan Zhu , Zeyu Sun , Tamas I. Gombosi

Helioseismology is the study of the variations in the internal structure and properties of the dynamics of the Sun from measurements of its surface oscillations. With the 2010 launch of the Solar Dynamics Observatory (SDO) we are…

Solar and Stellar Astrophysics · Physics 2015-06-11 Hamed Moradi

Far-side images of solar active regions have become one of the routine products of helioseismic observations, and are of importance for space weather forecasting by allowing the detection of sunspot regions before they become visible on the…

Astrophysics · Physics 2009-11-13 Thomas Hartlep , Junwei Zhao , Nagi N. Mansour , Alexander G. Kosovichev

We explore the general properties of near-surface flows around solar active regions. Helioseismic holography is applied to HMI Dopplergrams yielding nearly 5000 flow measurements of 336 unique active regions observed by the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2019-03-20 D. C. Braun

To create early warning capabilities for upcoming Space Weather disturbances, we have selected a dataset of 61 emerging active regions, which allows us to identify characteristic features in the evolution of acoustic power density to…

Solar and Stellar Astrophysics · Physics 2024-12-25 Spiridon Kasapis , Irina N. Kitiashvili , Alexander G. Kosovichev , John T. Stefan , Bhairavi Apte
‹ Prev 1 2 3 10 Next ›