Results 71 to 80 of about 10,692 (216)

Soft X-ray telescope (SXRT) [PDF]

The soft X-ray telescope (SXRT) will provide direct images of the solar corona with spatial resolution of about 1 arcsecond. These images will show the global structure of the corona, the location and area of coronal holes, and the presence of even the ...
Moore, R.
core   +4 more sources

Solar polar coronal hole - A mathematical simulation

The Astrophysical Journal, 1977
The northern polar region of the sun was studied during July 1973 by Munro and Jackson through use of the white-light coronagraph and the X-ray photographs produced by the Skylab mission. They described the northern polar hole as nearly axisymmetric and gave the geometry and density distribution under this approximation.
S. T. Suess, A. K. Richter, C. R. Winge, S. F. Nerney   +3 more
openaire   +1 more source

The spatial relationship between active regions and coronal holes and the occurrence of intense geomagnetic storms throughout the solar activity cycle [PDF]

Annales Geophysicae, 1998
We study the annual frequency of occurrence of intense geomagnetic storms (Dst < –100 nT) throughout the solar activity cycle for the last three cycles and find that it shows different structures.
S. Bravo, J. A. L. Cruz-Abeyro, D. Rojas
doaj   +1 more source

Statistical properties of coronal hole rotation rates: Are they linked to the solar interior?

, 2017
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.
Bagashvili, Salome R., Chargeishvili, Bidzina B., De Causmaecker, Patrick, Japaridze, Darejan R., Khodachenko, Maxim L., Kosovichev, Alexander G., Kukhianidze, Vasil, Poedts, Stefaan, Ramishvili, George, Shergelashvili, Bidzina M., Zaqarashvili, Teimuraz V.   +10 more
core   +1 more source

Solar wind from high‐latitude coronal holes at solar maximum [PDF]

Geophysical Research Letters, 2002
In this study we combine Ulysses' observations from the solar wind plasma (SWOOPS) and ion composition (SWICS) instruments to study high‐latitude coronal holes near solar maximum for the first time. While chromospheric and coronal composition signatures indicate that there is a unique type of solar wind, which flows from coronal holes, variations in ...
D. J. McComas, H. A. Elliott, R. von Steiger   +2 more
openaire   +1 more source

Ionosphere‐Thermosphere Coupling in the Northern Polar Region During the May 2024 Geomagnetic Superstorm

Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.
Abstract The May 2024 superstorm, as the most intense geomagnetic storm since 2003, caused a variety of disturbances in the magnetosphere‐ionosphere‐thermosphere system. This study investigates the long‐lasting electron density depletion in the polar region and the underlying ionosphere‐thermosphere coupling, based on a comprehensive set of ...
Lei Cai, Anita Aikio, G. P. Geethakumari, Heikki Vanhamäki, I. I. Virtanen, Shin‐ichiro Oyama, Yongliang Zhang, Jiaojiao Zhang, Marc Hairston   +8 more
wiley   +1 more source

On the Origin of the Sudden Heliospheric Open Magnetic Flux Enhancement During the 2014 Pole Reversal

The Astrophysical Journal
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.
Stephan G. Heinemann, Mathew J. Owens, Manuela Temmer, James A. Turtle, Charles N. Arge, Carl J. Henney, Jens Pomoell, Eleanna Asvestari, Jon A. Linker, Cooper Downs, Ronald M. Caplan, Stefan J. Hofmeister, Camilla Scolini, Rui F. Pinto, Maria S. Madjarska   +14 more
doaj   +1 more source

Lateral Confinement and the Remarkably Self-similar Nature of Coronal Pseudostreamer Mass Ejections

The Astrophysical Journal, 2023
Coronal mass ejections (CMEs) that originate from pseudostreamers, which separate coronal holes of the same magnetic polarity, are characterized by a narrow (∼5°–30°), fan-shaped appearance in white-light coronagraph images.
Y.-M. Wang, P. Hess
doaj   +1 more source

Interplanetary and solar surface properties of coronal holes observed during solar maximum [PDF]

Journal of Geophysical Research: Space Physics, 2003
Data from the Solar Wind Ion Composition Spectrometer (SWICS) on board the Ulysses spacecraft and synoptic maps from Kitt Peak are used to analyze the relatively short‐lived coronal holes which exist during the maximum phase of the solar activity cycle 23. They are compared with the persistent polar coronal holes which prevail around solar minimum.
Zhang, J., Woch, J., Solanki, S., von Steiger, R., Forsyth, R.   +4 more
openaire   +2 more sources

Deep Learning‐Based Prediction of High‐Speed Solar Wind Streams: Spatio‐Temporal Dependencies in Coronal Hole Dynamics

Earth and Space Science, Volume 13, Issue 1, January 2026.
Abstract High‐speed solar wind streams (HSS), originating from coronal holes (CH), are key drivers of space weather disturbances and heliospheric dynamics. However, forecasting HSS remains challenging due to the evolving morphology of CH. In this study, we present a deep learning‐based framework that models the spatiotemporal relationship between CH ...
J. J. Abraham‐Alowonle, Amr Hamada, Moataz Abdelwahab, Kanya Kusano, Ayman Mahrous   +4 more
wiley   +1 more source