Results 41 to 50 of about 5,669 (225)

How Are the Abnormally Hot Chromosphere and Corona Heated by the Solar Magnetic Fields?

open access: yesThe Astrophysical Journal
The corona is a structure possessed by stars, including the Sun. The abnormal heating of the solar corona and chromosphere is one of the greatest mysteries in modern astronomy.
K. J. Li   +5 more
doaj   +1 more source

Propagation Dynamics of Fast Electron Beam and Its Electron Cyclotron Maser Emission

open access: yesJournal of Geophysical Research: Space Physics, Volume 131, Issue 10, October 2026.
Abstract Fast electron beams (FEBs) and coherent radio bursts both are very common plasma activity phenomena in the cosmos. The electron cyclotron maser (ECM) instability driven by FEBs trapped in magnetic fields can directly amplify radio wave radiations.
Ling Chen   +3 more
wiley   +1 more source

Solar Spectroscopy and (Pseudo-)Diagnostics of the Solar Chromosphere

open access: yes, 2010
I first review trends in current solar spectrometry and then concentrate on comparing various spectroscopic diagnostics of the solar chromosphere. Some are actually not at all chromospheric but just photospheric or clapotispheric and do not convey ...
Raveendran, A.S.N.   +6 more
core   +1 more source

Solar Chromospheric Heating by Kinetic Alfvén Waves Based on the Three-fluid Model

open access: yesThe Astrophysical Journal
The heating mechanism of the solar chromosphere with a partially ionized plasma has been one of the challenging problems in solar physics. Kinetic Alfvén waves (KAWs) have been applied by many authors to study the heating of the corona and chromosphere ...
Jin-Run Ou   +3 more
doaj   +1 more source

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

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

Ionisation in the Solar Chromosphere [PDF]

open access: yesNature, 1920
IT is well known that the spectrum of the upper layers of the solar chromosphere is chiefly composed of those lines which are relatively more strengthened in the spark than in the arc, and which Sir Norman Lockyer originally styled enhanced lines. The best-known examples are the calcium H and K and the strontium pair (4216, 4077).
openaire   +1 more source

Determining the Magnetic Field in the Atmosphere of a Solar Active Region Observed by the CLASP2.1 Sounding Rocket Experiment

open access: yesThe Astrophysical Journal
We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment.
Ryohko Ishikawa   +19 more
doaj   +1 more source

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

open access: yesJournal 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   +11 more
wiley   +1 more source

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