Results 71 to 80 of about 37,593 (223)

A High-resolution, Inversion-based Synoptic Study of Solar Granulation

The Astrophysical Journal
The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun’s surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well known.
James W. Crowley, Ivan Milić, Gianna Cauzzi, Kevin Reardon   +3 more
doaj   +1 more source

Addressing Known Challenges in Solar Flare Forecasting I: Limb‐Flare Prediction With a 4π Full‐Heliosphere Framework

Space Weather, Volume 24, Issue 2, February 2026.
Abstract A demonstrated failure mode for operational solar flare forecasting is the inability to forecast flares that occur near, or just beyond, the solar limb. To address this shortcoming, we develop a “4π $4{\uppi }$” full‐heliosphere event forecasting framework and evaluate its statistical classification ability against this specific challenge.
K. D. Leka, Eric L. Wagner, Lisa Upton, Bibhuti Kumar Jha, Kiran Jain, Sara Petty   +5 more
wiley   +1 more source

PHYSICS OF NONDISSIPATIVE ULTRARELATIVISTIC PHOTOSPHERES [PDF]

International Journal of Modern Physics D, 2014
Recent observations, especially by the Fermi satellite, point out the importance of the thermal component in GRB spectra. This fact revives strong interest in photospheric emission from relativistic outflows. Early studies already suggested that the observed spectrum of photospheric emission from relativistically moving objects differs in shape from ...
openaire   +2 more sources

Solar polarimetry through the K I lines at 770 nm

, 2017
We characterize the K I D1 & D2 lines in order to determine whether they could complement the 850 nm window, containing the Ca II infrared triplet lines and several Zeeman sensitive photospheric lines, that was studied previously.
Anan, T., Carlsson, M., Cobo, B. Ruiz, Ichimoto, K., Katsukawa, Y., Kubo, M., Noda, C. Quintero, Oba, T., Shimizu, T., Suematsu, Y., Suárez, D. Orozco, Uitenbroek, H.   +11 more
core   +1 more source

Kinetic Modeling of Inertial Alfvén Waves in the Solar Corona: Implications for Heating and Particle Acceleration

Journal of Geophysical Research: Space Physics, Volume 131, Issue 1, January 2026.
Abstract Recent observations from Parker Solar Probe and Solar Orbiter highlight the importance of Alfvén waves in solar coronal heating and particle acceleration. In this study, we investigate inertial Alfvén waves (IAWs), which operate at electron inertial scales, as a potential mechanism for plasma heating and charged particle acceleration in the ...
S. Ayaz, Gary P. Zank, Imran A. Khan, Andreas Shalchi, L.‐L. Zhao, Yeimy J. Rivera   +5 more
wiley   +1 more source

Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts

The Astrophysical Journal
The prompt emission of gamma-ray bursts (GRBs) is supposed to be released from the relativistic jet launched from the central engine. Apart from the nonthermal nature of spectra in the majority of GRBs, there is evidence for the presence of quasi-thermal
Ding-Fang Hu, Jin-Jun Geng, Hao-Xuan Gao, Jing-Zhi Yan, Xue-Feng Wu   +4 more
doaj   +1 more source

The height dependence of temperature - velocity correlation in the solar photosphere

, 2007
We derive correlation coefficients between temperature and line-of-sight velocity as a function of optical depth throughout the solar photosphere for the non-magnetic photosphere and a small area of enhanced magnetic activity. The maximum anticorrelation
Koza, J., Kucera, A., Rybák, J., Wöhl, H.   +3 more
core  

Non linear evolution of Alfvén wave in the solar atmosphere [PDF]

, 2005
We investigate the non-linear evolution of Alfvén waves in the solar atmosphere and wind, from the photosphere out to the Earth’s orbit. Photosphere and chromosphere are modeled as isothermal layers in static equilibrium, connecting across the transition
Oughton, Sean, Velli, M., Verdini, A.
core   +1 more source

Stratigraphy of Carbonate‐Bearing Rocks at the Margin of Jezero Crater, Mars: Evidence for Shoreline Processes?

Journal of Geophysical Research: Planets, Volume 131, Issue 1, January 2026.
Abstract Martian carbonate‐bearing rocks are compelling targets for exploration because they preserve detailed records of past aqueous processes, climate, and habitability. The Margin unit in Jezero crater is a distinct olivine‐ and carbonate‐bearing unit stratigraphically underlying the western fan, lining the inner margin of the western crater rim ...
Alexander J. Jones, Sanjeev Gupta, Robert Barnes, Briony H. N. Horgan, Kenneth H. Williford, Gerhard Paar, Kathryn. M. Stack, Bradley J. Garzcynski, Eleni Ravanis, Candice C. Bedford, Justin I. Simon, Athanasios Klidaras, Linda C. Kah, James F. Bell, Justin Maki, Stephen W. Lokier, Adrian Brown, Nathan R. Williams, Sanna Alwmark, Jorge I. Núñez, Fred Calef, Larry Crumpler, Alicia Vaughan, Libby R. W. Ives, Sam Gwizd, Ken Farley, Christian Tate, Nicolas Randazzo, Olivier Beyssac, Gwénaël Caravaca   +29 more
wiley   +1 more source

Solar Vortex Tubes. III. Vorticity and Energy Transport

The Astrophysical Journal
This study investigated the mechanisms of vorticity generation and the role of vortex tubes in plasma heating and energy transport. Vortex tubes were identified using the instantaneous vorticity deviation technique in the MURaM data set of a simulated ...
Suzana S. A. Silva, Gary Verth, Istvan Ballai, Erico L. Rempel, Sergiy Shelyag, Luiz A. C. A. Schiavo, Tiago F. P. Gomes, Viktor Fedun   +7 more
doaj   +1 more source