Results 21 to 30 of about 293,183 (281)
Numerical Simulation of Coronal Waves Interacting with Coronal Holes. II. Dependence on Alfvén Speed Inside the Coronal Hole [PDF]
The Astrophysical Journal, 2018 Abstract We used our newly developed magnetohydrodynamic (MHD) code to perform 2.5D simulations of a fast-mode MHD wave interacting with coronal holes (CHs) of varying Alfvén speed that result from assuming different CH densities. We find that this interaction leads to effects like reflection, transmission, stationary fronts at the CH ...
Isabell Piantschitsch +6 more
openaire +3 more sources
High-frequency Alfven waves in multi-ion coronal plasma : observational implications [PDF]
, 2005 We investigate the effects of high-frequency (of order ion gyrofrequency) Alfvén and ion-cyclotron waves on ion emission lines by studying the dispersion of these waves in a multi-ion coronal plasma.
Ofman, L. (Leon) +3 more
core +1 more source
The Sun's global photospheric and coronal magnetic fields : observations and models [PDF]
, 2012 2012LRSP....9....6M Funding: STFC, the Leverhulme Trust and European Commission’s Seventh Framework Programme (FP7/2007-2013) under the grant agreement SWIFF (project no.
Anthony Yeates +6 more
core +1 more source
The Astrophysical Journal, 2009 Here, we explore the nature of small-scale jet-like structures and their possible relation to explosive events and other known transient features, like spicules and macrospicules, using high-resolution spectroscopy obtained with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurements of Emitted Radiation instrument.
Scullion, E. +4 more
openaire +2 more sources
Long-term evolution of solar coronal holes [PDF]
, 2023 Solar coronal holes are regions of open magnetic field lines in the solar corona. They are the source region of high-speed solar wind streams that play an important role for geomagnetic activity and are the most important driver of energetic particle ...
Hamada, Amr
core +1 more source
Investigating Alfvénic wave propagation in coronal open-field regions [PDF]
, 2015 The physical mechanisms behind accelerating solar and stellar winds are a long-standing astrophysical mystery, although recent breakthroughs have come from models invoking the turbulent dissipation of Alfvén waves.
Morton, Richard +2 more
core +1 more source
DIPOLAR EVOLUTION IN A CORONAL HOLE REGION [PDF]
The Astrophysical Journal, 2009 Using observations from the SOHO, STEREO and Hinode, we investigate magnetic field evolution in an equatorial coronal hole region. Two dipoles emerge one by one. The negative element of the first dipole disappears due to the interaction with the positive element of the second dipole. During this process, a jet and a plasma eruption are observed.
Yang, S., Zhang, J., Borrero, J.
openaire +3 more sources
Antarctic Record, 1980 This is an attempt to identify the causes of geomagnetic storms which occurred during a year and a half from January 1977 to June 1978. The assignment of geomagnetic storm causation to appropriate coronal holes or solar flares has been made by ...
Katsuhide MARUHASHI, Takahiroo ISHI
doaj +1 more source
Velocity Structure of Jets in a Coronal Hole [PDF]
Publications of the Astronomical Society of Japan, 2007 Abstract The velocity structures of jets in a coronal hole have been derived for the first time. Hinode observations revealed the existence of many bright points in coronal holes. They are loop-shaped and sometimes associated with coronal jets. Spectra obtained with the Extreme-ultraviolet Imaging Spectrometer aboard Hinode were analyzed
Kamio, Suguru +6 more
openaire +2 more sources
The Merging of a Coronal Dimming and the Southern Polar Coronal Hole
The Astrophysical Journal, 2023 Abstract We report on the merging between the southern polar coronal hole and an adjacent coronal dimming induced by a coronal mass ejection on 2022 March 18, resulting in the merged region persisting for at least 72 hr. We use remote sensing data from multiple co-observing spacecraft to understand the physical processes during this ...
Nawin Ngampoopun +6 more
openaire +4 more sources