Results 21 to 30 of about 332 (133)

Observations, analysis and interpretation with non-LTE of chromospheric structures on the Sun [PDF]

, 2022
Die Sonne besteht u.a. aus einer Schicht, genannt die Chromsphere, die sich über die weitaus leuchtkräftigere Photosphere ausdehnt. In dieser dünnen Schicht ist die Dynamik des Plasmas hauptsächlich von der der Magnetfelder beherrscht, wodurch neue und komplizierte Phänomene zustande kommen.
Sánchez-Andrade Nuño, Bruno, Kneer, Franz, Georg-August-Universität Göttingen, Kollatschny, Wolfram   +3 more
openaire   +3 more sources

Chromosphere of the quiet sun

Astronomy & Astrophysics
Context. The solar chromosphere is a dynamic and crucial interface between the solar interior and its interplanetary environment, regulating how energy is locally deposited into heat and transported into the upper atmospheric layers.
Q. Noraz, M. Carlsson, G. Aulanier
openaire   +4 more sources

On the Magnetic Nature of Quiet-Sun Chromospheric Grains

The Astrophysical Journal Letters, 2023
Abstract Ca ii K grains, i.e., intermittent, short-lived (about 1 minute), periodic (2–4 minutes), pointlike chromospheric brightenings, are considered to be the manifestations of acoustic waves propagating upward from the solar surface and developing into shocks in the chromosphere.
María Jesús Martínez González, Tanausú del Pino Alemán, Adur Pastor Yabar, C. Quintero Noda, Andrés Asensio Ramos   +4 more
openaire   +2 more sources

An Operational Daily‐Filtered Dominion Radio Astrophysical Observatory F10.7 cm Solar Radio Flux Product

Earth and Space Science, Volume 13, Issue 9, September 2026.
Abstract The F10.7 solar radio flux density, or F10.7, is a disk‐integrated measure of the Sun's total emission at 10.7 cm (2.8 GHz) and is a widely‐used proxy of solar activity. F10.7 emissions primarily originate from the Sun's upper chromosphere and lower corona. High‐frequency, transient “radio bursts” can dramatically increase the magnitude of F10.
C. Kuester, O. M. Coddington, C. Lindholm, C. L. Peck   +3 more
wiley   +1 more source

Chromospheric activity of nearby Sun-like stars [PDF]

Astronomy & Astrophysics, 2020
Context.The chromospheric emission in the cores of the Ca IIH & K lines of late-type dwarfs is a well known indicator of magnetic activity that decreases with increasing stellar age.Aims.I use this indicator to investigate the formation history of nearby G- and early K-type stars with origins at galactocentric distances similar to that of the ...
openaire   +1 more source

Comparing Solar Structure Detection Methods in SDO/AIA Observations and the Application to Raw Uncalibrated Data

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 3, June 2026.
Abstract Recent advances in solar physics increasingly rely on automated identification of coronal structures using machine learning. Yet most studies emphasize scientific performance without evaluating feasibility for onboard deployment to prioritize downlink observations.
P. Gonidakis, F. Carella, E. Dineva, H‐J. Jeong, P. Antunes, A. Podobas, S. Raptis, V. Toy‐Edens, M. Jin, S. Poedts, J. Magdalenic, G. Miloshevich   +11 more
wiley   +1 more source

Advancing Heliophysics and Space Weather Modeling Through Open Science

Space Weather, Volume 24, Issue 6, June 2026.
Abstract We present a community‐wide effort to develop a strategy and action plan to advance heliophysics and space weather modeling through open science. While open science has the potential to enhance the quality and pace of scientific discovery, its application to scientific modeling requires more careful consideration regarding open data and open ...
C. Corti, M. M. Kuznetsova, M. A. Reiss, J. Yue, J. Karpen, C. N. Arge, F. Bacchini, C. Bard, S. Bruinsma, R. M. Caplan, L. K. S. Daldorff, P. J. Deka, C. R. DeVore, S. Elvidge, N. Ganushkina, J. D. Huba, B. V. Jackson, V. Jordanova, J. A. Linker, H. Liu, J. G. Luhmann, S. Markidis, P. Mayank, V. Merkin, N. Moens, D. Odstrcil, Y. A. Omelchenko, M. Palmroth, S. Poedts, A. J. Ridley, Y. Shou, V. Tenishev, D. R. Themens, G. Toth, W. Wang, R.‐P. Wilhelm, M. A. Young, B. Cecconi, M.‐Y. Chou, D. De Zeeuw, G. L. Delzanno, C. Didigu, M. El Alaoui, S. Fung, J. Green, Z. Huang, L. K. Jian, L. J. Landwer, M. Lesko, P. MacNeice, A. Masson, M. L. Mays, P. M. Mehta, M. S. Miesch, E. Palmerio, M. Petrenko, E. Provornikova, L. Rastätter, L. Rusaitis, N. Sachdeva, E. Samara, D. Sur, A. Taktakishvili, J. Topper, T. Tsui, C. Verbeke, J. Wang, C. Wiegand, M. Wiltberger, Y. Zheng, M. M. Bisi, M. K. Georgoulis, T. Kodikara, T. Pulkkinen, A. Chartier, D. da Silva, A. Faturahman, K. Garcia‐Sage, D. Kondrashov, V. E. Ledvina, W. Liu, C. Pandey, E. Resnick, C. Shi, R. S. Weigel, K. Whitman, I. Zakharenkova, K. Zhang   +87 more
wiley   +1 more source

Spectral Irradiance Observations and Projections for Solar Cycle 25

Earth and Space Science, Volume 13, Issue 4, April 2026.
Abstract The Ozone Monitoring Instrument (OMI) on the Aura satellite makes near‐daily measurements of solar spectral irradiance (SSI) at wavelengths between 265 and 500 nm for instrument calibration purposes. The low degradation and exceptional stability of OMI's calibration during its lifetime facilitates the creation of a new 18‐year OMI Version 7 ...
Matthew T. DeLand, Sergey V. Marchenko, Judith L. Lean, Odele Coddington   +3 more
wiley   +1 more source

Parker Solar Probe Observations of Proton Core‐Beam Distributions in Heliospheric Current Sheet Region: Quasilinear Instability Analysis Combined With Collisional Relaxation

Journal of Geophysical Research: Space Physics, Volume 131, Issue 4, April 2026.
Abstract Parker Solar Probe has been proven as instrumental for the observation of young solar wind. During the encounters E‐07 and E‐08, PSP recorded the core plus beaming protons crossing the heliospheric current Sheet region. When the observed PSP data is plotted in the temperature ratio versus parallel beta space, it is found that the occurrence ...
M. Rashid, P. H. Yoon, J. Huang, C. Salem, M. Sarfraz, S. Alnussirat, R. A. López, J. Seough, H. Xie, D. Larson, R. Livi   +10 more
wiley   +1 more source

Dynamic models of the sun from the convection zone to the chromosphere [PDF]

Proceedings of the International Astronomical Union, 2006
AbstractThe chromosphere in internetwork regions of the quiet Sun was regarded as a static and homogeneous layer for a long time. Thanks to advances in observations and numerical modelling, the wave nature of these atmospheric regions received increasing attention during the last decade.
openaire   +2 more sources