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Related papers: Automated Coronal Hole Detection using Local Inten…

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New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer sub-structures within coronal loop cross sections, in order to…

Solar and Stellar Astrophysics · Physics 2015-06-22 Eamon Scullion , Luc Rouppe van der Voort , Sven Wedemeyer , Patrick Antolin

A comparison between a Coronal Hole (CH) and the adjacent Quiet-Sun (QS) has been performed using spectroscopic diagnostics of Hinode/ the EUV Imaging Spectrometer (EIS). Coronal funnels play an important role in the formation and…

Solar and Stellar Astrophysics · Physics 2015-11-04 P. Kayshap , D. Banerjee , A. K. Srivastava

Many scientists use coronal hole (CH) detections to infer open magnetic flux. Detection techniques differ in the areas that they assign as open, and may obtain different values for the open magnetic flux. We characterize the uncertainties…

Coronal holes (CHs) are widely considered as the main sources of high-speed solar wind streams. We validate this thesis comparing the smoothed time series of solar wind speed measured by Advanced Composition Explorer (ACE) and various…

Solar and Stellar Astrophysics · Physics 2025-07-30 Egor Illarionov , Andrey Tlatov , Ivan Berezin , Nadezhda Skorbezh

We present a method that isolates time-varying components from coronagraph and EUV images, allowing sub-streamer transients propagating within streamers to be tracked from the low to high corona. The method uses a temporal bandpass filter…

Solar and Stellar Astrophysics · Physics 2021-10-04 Nathalia Alzate , Huw Morgan , Nicholeen Viall , Angelos Vourlidas

To study the dynamics of coronal holes and the role of waves in the acceleration of the solar wind, spectral observations were performed over polar coronal hole regions with the SUMER spectrometer on SoHO and the EIS spectrometer on Hinode.…

Solar and Stellar Astrophysics · Physics 2009-05-08 D. Banerjee , L. Teriaca , G. R. Gupta , S. Imada , G. Stenborg , S. K. Solanki

We present a concept study of a solar wind forecasting method for Earth, based on persistence modeling from STEREO in-situ measurements combined with multi-viewpoint EUV observational data. By comparing the fractional areas of coronal holes…

Solar and Stellar Astrophysics · Physics 2018-02-01 M. Temmer , J. Hinterreiter , M. A. Reiss

We derive a simple analytical model for the propagation of HSSs from the Sun to Earth and thereby show how the area of coronal holes and the size of their boundary regions affect the HSS velocity, temperature, and density near Earth. We…

We investigate the statistics of 288 low-latitude coronal holes extracted from SDO/AIA-193 filtergrams over the time range 2011/01/01 to 2013/12/31. We analyse the distribution of characteristic coronal hole properties, such as the areas,…

Solar and Stellar Astrophysics · Physics 2017-02-08 S. J. Hofmeister , A. Veronig , M. A. Reiss , M. Temmer , S. Vennerstrom , B. Vršnak , B. Heber

This paper presents results of comparison between observations of coronal holes in the UV (SOHO EIT) and microwave emission (17, 5.7 GHz, 327 and 150.9 MHz, NoRH, SSRT and Nancy radioheliographs), and solar wind parameters, according to the…

Solar and Stellar Astrophysics · Physics 2015-05-20 D. Prosovetsky , I. Myagkova

Events in the solar corona are often widely separated in their timescales, which can allow them to be identified when they would otherwise be confused with emission from other sources in the corona. Methods for cleanly separating such…

Solar and Stellar Astrophysics · Physics 2016-02-01 Joseph Plowman

Accurate forecasting of the solar wind has grown in importance as society becomes increasingly dependent on technology that is susceptible to space weather events. This work describes an inner boundary condition for ambient solar wind…

Space Physics · Physics 2022-07-22 Kaine A. Bunting , Huw Morgan

Small-scale ephemeral coronal holes may be a recurring feature on the solar disk, but have received comparatively little attention. These events are characterized by compact structure and short total lifetimes, substantially less than a…

Solar and Stellar Astrophysics · Physics 2019-08-07 Andrew R. Inglis , Rachel E. O'Connor , W. Dean Pesnell , Michael S. Kirk , Nishu Karna

Coronal hole boundaries are the interfaces between closed and open magnetic field regions in the solar atmosphere. Many fundamental processes take place at these regions, including magnetic reconnection that is responsible for solar wind…

Macroscopic wave and oscillatory phenomena ubiquitously detected in the plasma of the corona of the Sun are interpreted in terms of magnetohydrodynamic theory. Fast and slow magnetoacoustic waves are clearly distinguished in observations.…

Solar and Stellar Astrophysics · Physics 2024-04-02 Valery M. Nakariakov , Sihui Zhong , Dmitrii Y. Kolotkov , Rebecca L. Meadowcroft , Yu Zhong , Ding Yuan

We present a detailed analysis of oxygen ion velocity distributions in the extended solar corona, based on observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at solar minimum…

Astrophysics · Physics 2009-11-13 Steven R. Cranmer , Alexander V. Panasyuk , John L. Kohl

The detection and analysis of the solar coronal holes (CHs) is an important field of study in the domain of solar physics. Mainly, it is required for the proper prediction of the geomagnetic storms which directly or indirectly affect…

Solar and Stellar Astrophysics · Physics 2024-03-28 Sanmoy Bandyopadhyay , Suman Kundu

We study the properties of 115 coronal holes in the time-range from 2010/08 to 2017/03, the peak velocities of the corresponding high-speed streams as measured in the ecliptic at 1 AU, and the corresponding changes of the Kp index as marker…

Solar and Stellar Astrophysics · Physics 2018-04-27 Stefan J. Hofmeister , Astrid Veronig , Manuela Temmer , Susanne Vennerstrom , Bernd Heber , Bojan Vršnak

Coronal holes are the dark patches in the solar corona associated with relatively cool, less dense plasma and unipolar fields. The fast component of the solar wind emanates from these regions. Several observations reveal the presence of…

Solar and Stellar Astrophysics · Physics 2016-03-09 D. Banerjee , S. Krishna Prasad

The present paper discusses results of a statistical study of the characteristics of coronal hole (CH) rotation in order to find connections to the internal rotation of the Sun. The goal is to measure CH rotation rates and study their…