Results 51 to 60 of about 285 (167)

Solar Wind Heavy Ions and Alpha Particles Within Earth's Magnetosphere and Their Variability With Upstream Conditions

Journal of Geophysical Research: Space Physics, Volume 130, Issue 8, August 2025.
Abstract Working toward the goal of understanding solar wind (SW) entry to the Earth's magnetosphere, this study examines solar‐origin ion composition in the magnetotail. During its trajectory, Wind spent a significant amount of time in the Earth's magnetotail, where its SupraThermal Ion Composition Spectrometer (STICS) measured the mass and mass per ...
S. Colón‐Rodríguez, M. W. Liemohn, J. M. Raines, S. T. Lepri   +3 more
wiley   +1 more source

The Ubiquity of Twisted Flux Ropes in the Quiet Sun

The Astrophysical Journal Letters
Models and observations have demonstrated that twisted flux ropes (TFRs) play a significant role in the structure and eruptive dynamics of active regions.
Tahar Amari, Aurélien Canou, Marco Velli, Zoran Mikic, Frederic Alauzet, Eric Buchlin, Jean-François Luciani, Jean-Jacques Aly, Lucas A. Tarr   +8 more
doaj   +1 more source

Cause of Chromospheric Opposite Polarity Intrusions Discovered in Sunrise III/SCIP Data: MURaM-ChE Simulations Point to Twisted Flux Ropes

The Astrophysical Journal Letters
The Sunrise Chromospheric Infrared spectroPolarimeter (SCIP) instrument on board the balloon-borne S unrise iii observatory provided new high-resolution observations of the solar chromosphere in the Ca ii   λ 854.2 nm line.
Patrick A. Ondratschek, Damien F. Przybylski, Robert H. Cameron, H. N. Smitha, Sami K. Solanki, Masahito Kubo, Andreas Lagg, Achim Gandorfer, Jose Carlos del Toro Iniesta, Yukio Katsukawa, Pietro Bernasconi, Thomas Berkefeld, Alex Feller, Tino L. Riethmüller, Alberto Álvarez-Herrero, David Orozco Suárez, Bianca Grauf, Michael Carpenter, Alexander Bell, Valentín Martínez Pillet, Laurent Gizon, Francisco Javier Bailén, Julian Blanco Rodríguez, Juan Sebastián Castellanos Durán, Edvarda Harnes, Johannes Hoelken, Francisco A. Iglesias, Ryohtaroh T. Ishikawa, Yusuke Kawabata, Takuma Matsumoto, Takayoshi Oba, Azaymi L. Siu-Tapia, Hanna Strecker, Dušan Vukadinović, Hirohisa Hara, Toshifumi Shimizu   +35 more
doaj   +1 more source

Slow Solar Wind: Origin in an Independent Small‐Scale Solar Dynamo

Geophysical Research Letters, Volume 52, Issue 13, 16 July 2025.
Abstract Separation of the solar wind (SW) into three flow types (coronal mass ejections (CMEs), high speed streams (HSSs), and slow solar wind (SSW)) reveals an inverse relationship between the percentage of time Earth spends in SSW during a year and its annually averaged magnetic field strength (B).
E. W. Cliver, I. G. Richardson, S. F. Martin   +2 more
wiley   +1 more source

Wave Reflection in the Solar Atmosphere

The Astrophysical Journal
We present evidence supporting wave reflection in the lower solar chromosphere based on helioseismic analysis of multi-height Doppler data from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager and the Magneto-Optical filters at Two Heights
Varun Chaturmutha, Bernhard Fleck, Stuart M. Jefferies   +2 more
doaj   +1 more source

Quasi‐Periodic Pulsations in Ionospheric TEC Synchronized With Solar Flare EUV Emission

Journal of Geophysical Research: Space Physics, Volume 130, Issue 4, April 2025.
Abstract The extreme ultraviolet (EUV) and X‐ray radiation emitted during solar flares has been shown to significantly increase the electron density of the Earth's ionosphere. During flares, quasi‐periodic pulsations in X‐ray flux originating in the corona have previously been linked to subsequent pulsations in the Earth's ionospheric D‐region. Similar
Aisling N. O’Hare, Susanna Bekker, Laura A. Hayes, Ryan O. Milligan   +3 more
wiley   +1 more source

Constraints on Acoustic Wave Energy Fluxes and Radiative Losses in the Solar Chromosphere from Non-LTE Inversions

The Astrophysical Journal
Accurately assessing the balance between acoustic wave energy fluxes and radiative losses is critical for understanding how the solar chromosphere is thermally regulated.
J. M. da Silva Santos, M. Molnar, I. Milić, M. Rempel, K. Reardon, J. de la Cruz Rodríguez   +5 more
doaj   +1 more source

First Observations of a Geomagnetic Superstorm With a Sub‐L1 Monitor

Space Weather, Volume 23, Issue 3, March 2025.
Abstract Forecasting the geomagnetic effects of solar coronal mass ejections (CMEs) is currently an unsolved problem. CMEs, responsible for the largest values of the north‐south component of the interplanetary magnetic field, are the key driver of intense and extreme geomagnetic activity.
E. Weiler, C. Möstl, E. E. Davies, A. M. Veronig, U. V. Amerstorfer, T. Amerstorfer, J. Le Louëdec, M. Bauer, N. Lugaz, V. Haberle, H. T. Rüdisser, S. Majumdar, M. Reiss   +12 more
wiley   +1 more source

Comparison of Coronal Hole and Quiet-Sun Chromosphere Using IRIS Mg ii h and k Observations of Polar Off-limb Regions

The Astrophysical Journal
Solar quiet regions are divided into coronal hole regions (CH) and quiet-Sun regions (QS). The global magnetic field in CH is considered open to interplanetary space, while that in QS is closed.
Akiko Tei, Stanislav Gunár, Takenori J. Okamoto   +2 more
doaj   +1 more source

Semiempirical Models of the Solar Atmosphere. II. The Quiet‐Sun Low Chromosphere at Moderate Resolution

The Astrophysical Journal, 2007
We present a new, one-dimensional model of the solar atmosphere (called SRPM 305) at moderate angular resolution (~1''-2''). Key characteristics of the SRPM 305 model include (1) a minimum temperature of ~3800 K at a gas pressure of ~80 dyne cm-2 and (2) a rapid temperature rise above the temperature-minimum layer that results in substantial ...
J. M. Fontenla, K. S. Balasubramaniam, J. Harder   +2 more
openaire   +1 more source