Results 71 to 80 of about 1,198,926 (208)

Global Effect of Long‐Lasting 07–12 October 2024 Geomagnetic Storms During the Transition From a Strong (G3) to a Severe (G4) on the Geomagnetic Field and Ionospheric Parameters Distribution

open access: yesSpace Weather, Volume 24, Issue 7, July 2026.
Abstract This study investigates the co‐evolution of geomagnetic field disturbances with ionospheric parameters and their characteristic latitudinal signatures by conducting a location and time‐dependent analysis of the 07–12 October 2024 events, to fill crucial gaps in understanding the coupled response of the magnetosphere‐ionosphere system. This has
Yekoye Asmare Tariku
wiley   +1 more source

Current sheets in the solar corona : formation, fragmentation and heating [PDF]

open access: yes, 2011
In this thesis we investigate current sheets in the solar corona. The well known 1D model for the tearing mode instability is presented, before progressing to 2D where we introduce a non-uniform resistivity.
Bowness, Ruth
core   +2 more sources

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

open access: yesThe 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   +14 more
doaj   +1 more source

Development and Cancellation of Long‐Duration Positive Ionospheric Storms: Both Changes of the F2‐Layer Peak Height and O/N2 Ratio Can Be Decisive

open access: yesSpace Weather, Volume 24, Issue 7, July 2026.
Abstract For decades, two competing hypotheses on the key drivers of mid‐latitude long‐duration positive ionospheric storms (LDPS) have been considered: (a) an increase of the F2‐layer peak height (hmF2) and (b) an increase in the atomic oxygen to molecular nitrogen density ratio (O/N2).
D. V. Kotov   +15 more
wiley   +1 more source

An Empirical Model of a Polar Coronal Hole at Solar Minimum

open access: yesThe Astrophysical Journal, 1999
We present a comprehensive and self-consistent empirical model for several plasma parameters in the extended solar corona above a polar coronal hole. The model is derived from observations with the SOHO Ultraviolet Coronagraph Spectrometer (UVCS/SOHO) during the period between 1996 November and 1997 April.
CRANMER S. R.   +30 more
openaire   +1 more source

Mercury's Eccentric Orbit as a Driver of Significant “Seasonal” Change in Upstream Solar Wind Forcing

open access: yesGeophysical Research Letters, Volume 53, Issue 12, 28 June 2026.
Abstract Mercury experiences the most intense and variable solar wind (SW) conditions in the solar system due to its close, eccentric orbit about the Sun. In addition to variation driven by coronal source and solar cycle, the SW arriving at Mercury varies periodically as the planet's heliocentric distance changes by over 50% per orbit.
Ryan M. Dewey   +17 more
wiley   +1 more source

Coronal Holes [PDF]

open access: yes, 2016
Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind ...
Cranmer, Steven
core   +1 more source

The propagation and damping of slow magnetoacoustic waves in the solar atmosphere [PDF]

open access: yes, 2012
The propagation and damping of slow magnetoacoustic waves in the solar atmosphere is investigated, with particular emphasis placed on waves with periodicities of five minutes. The basic model of a uniform temperature loop is extended by the addition of
Owen, Nicholas Robert
core   +2 more sources

Coronal and Chromospheric Dynamics of a Coronal Hole Bright Point

open access: yesThe Astrophysical Journal
Data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic Magnetic Imager on board the Solar Dynamics Observatory and from the Interface Region Imaging Spectograph, are used to study the evolution at different atmospheric layers of a bright ...
Ana Cristina Cadavid, Mari Paz Miralles
doaj   +1 more source

Field-aligned currents are strongly modulated by corotating solar wind high-speed streams

open access: yesJournal of Space Weather and Space Climate
Birkeland field-aligned currents (FACs) are associated with solar wind-magnetosphere energy coupling leading to substorms/convection events. FAC intensity enhancements have been studied during geomagnetic storms driven by interplanetary coronal mass ...
Hajra Rajkumar   +8 more
doaj   +1 more source

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