Results 31 to 40 of about 3,072 (224)

Resonance Lines in the Solar Chromosphere [PDF]

open access: yesSymposium - International Astronomical Union, 1970
Stigmatic balloon spectra of the Sun in the vicinity of 2800 Å were obtained on September 22, 1968 and April 30, 1969. We compare the observed profiles of the H and K lines of ionized magnesium with the computed profiles of Athay and Skumanich and of Dumont. The discrepancy between observed and computed profiles of the Mgii lines is considerable. It is
openaire   +1 more source

Element Abundances in Impulsive Solar Energetic Particle Events

open access: yesThe Astrophysical Journal, 2023
We outline and discuss a model for the enhanced abundances of trans-Fe elements in impulsive solar energetic particle (SEP) events, where large mass-dependent abundance enhancements are frequently seen.
J. Martin Laming, Natsuha Kuroda
doaj   +1 more source

Observations of the upper solar chromosphere with SUMER [PDF]

open access: yes, 2003
The structure and dynamics of the solar chromosphere are still matters of debate. The chromospheric network reflecting the supergranulation of the outer convection zone of the Sun is a prominent feature of the lower solar atmosphere that extends into the
Kalkofen, W.   +3 more
core   +1 more source

The Magnetic Sensitivity of the (250–278 nm) Fe ii Polarization Spectrum

open access: yesThe Astrophysical Journal, 2023
This paper presents a theoretical investigation of the polarization and magnetic sensitivity of the near-ultraviolet (near-UV) solar spectral lines of Fe ii between 250 and 278 nm.
David Afonso Delgado   +2 more
doaj   +1 more source

The Impact of Multifluid Effects in the Solar Chromosphere on the Ponderomotive Force under SE and NEQ Ionization Conditions

open access: yesThe Astrophysical Journal, 2023
The ponderomotive force has been suggested to be the main mechanism to produce the so-called first ionization potential (FIP) effect—the enrichment of low-FIP elements observed in the outer solar atmosphere, in the solar wind, and in solar energetic ...
Juan Martínez-Sykora   +5 more
doaj   +1 more source

Observational signatures of waves and flows in the solar corona [PDF]

open access: yes, 2015
DM acknowledges support of a Royal Society University Research Fellowship and a KU Leuven Research Council senior research fellowship (SF/12/008). The research leading to these results has also received funding from the European Commission Seventh ...
Antolin, Patrick   +3 more
core   +1 more source

Advancing Heliophysics and Space Weather Modeling Through Open Science

open access: yesSpace 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   +87 more
wiley   +1 more source

Propagation and damping of MHD waves in the solar atmosphere [PDF]

open access: yes, 2015
Quasi-periodic disturbances have been observed in the outer solar atmosphere for many years. Although first interpreted as upflows (Schrijver et al.
Kiddie, Greg
core  

The New Composite Solar Flare Index from Solar Cycle 17 to Cycle 24 (1937 – 2020) [PDF]

open access: yes, 2022
The chromosphere is a highly dynamic outer plasma layer of the Sun. Its physical processes accounting for the variability are poorly understood. We reconstructed the solar chromospheric flare index (SFI) to study the solar chromospheric variability from ...
Acosta Jara, Jose Nemesio
core   +1 more source

Spectral Irradiance Observations and Projections for Solar Cycle 25

open access: yesEarth 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   +3 more
wiley   +1 more source

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