Results 41 to 50 of about 1,559,234 (209)

Chromospheric seismology above sunspot umbrae [PDF]

, 2015
Context: The acoustic resonator is an important model for explaining the three-minute oscillations in the chromosphere above sunspot umbrae. The steep temperature gradients at the photosphere and transition region provide the cavity for the acoustic ...
G. J. J. Botha, B. Snow, Snow, Ben, Botha, Gert, Regnier, Stephane, S. Régnier   +5 more
core   +1 more source

Model solar chromosphere with prescribed heating

The Astrophysical Journal, 1989
Computed model solar chromospheres for prescribed departures from radiative equilibrium are specified in terms of the local mechanical (nonradiative) heat input. The computations are fully non-LTE and include millions of spectral lines. From the variety of models considered, the requirements on the heat input for a positive temperature gradient, dT/dh,
Lawrence S. Anderson, R. Grant Athay
openaire   +1 more source

Is the Solar Chromosphere Heated by Acoustic Waves? [PDF]

The Astrophysical Journal, 2007
Space observations with TRACE have measured only 10% of the energy flux required to heat the nonmagnetic part of the solar chromosphere and have thereby called into question the theory of chromospheric heating by acoustic waves. To explain the deficit in the measured flux, heating by processes related to the magnetic field and the limited spatial ...
openaire   +1 more source

Chromospheric heating by magnetohydrodynamic waves and instabilities [PDF]

, 2021
The importance of the chromosphere in the mass and energy transport within the solar atmosphere is now widely recognised. This review discusses the physics of magnetohydrodynamic (MHD) waves and instabilities in large-scale chromospheric structures as ...
Srivastava, Abhishek Kumar, Jess, D. B.; id_orcid, Jess, D.B., Jess, David B., M. Goossens, Cally, P S, A. K. Srivastava, P. S. Cally, D. B. Jess, Murawski, K., Ballester, J.L., Carlsson, Mats, Ballester, Jose Luis, Khomenko, Elena, Murawski, Kris, Zaqarashvili, T.V., M. Carlsson, Cally, P.S., Goossens, M, Mathioudakis, M., Ballester, J L, M. Mathioudakis, Carlsson, M, Khomenko, E., Zaqarashvili, T V, J. L. Ballester, E. Khomenko, Srivastava, A.K., Srivastava, A K, K. Murawski, Goossens, M., Khomenko, E, Cally, Paul Stuart, Mathioudakis, Mihalis, Carlsson, M., T. V. Zaqarashvili, Murawski, K, Zaqarashvili, Teimuraz   +37 more
core   +1 more source

Newly Discovered Source of Turbulence and Heating in the Solar Chromosphere [PDF]

The Astrophysical Journal Letters, 2020
Abstract Above the Sun’s luminous photosphere lies the solar chromosphere, where the temperature increases from below 4000 K to over 1 million K. Though physicists do not understand the origin of these increases, they know it powers the solar wind with enormous consequences for the entire solar system.
Meers Oppenheim, Yakov Dimant, William Longley, Alex C. Fletcher   +3 more
openaire   +1 more source

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

The 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, Ling Chen, De-Jin Wu, Chuan-Bing Wang   +3 more
doaj   +1 more source

HEATING OF THE PARTIALLY IONIZED SOLAR CHROMOSPHERE BY WAVES IN MAGNETIC STRUCTURES [PDF]

The Astrophysical Journal Letters, 2016
ABSTRACT In this paper, we show a “proof of concept” of the heating mechanism of the solar chromosphere due to wave dissipation caused by the effects of partial ionization. Numerical modeling of non-linear wave propagation in a magnetic flux tube, embedded in the solar atmosphere, is performed by solving a system of single-fluid quasi ...
S. Shelyag, E. Khomenko, A. de Vicente, D. Przybylski   +3 more
openaire   +3 more sources

Benchmarking Deep Learning Models for Real‐Time Prediction of Post‐Peak Solar Flare Irradiance Using FISM2 Data

Space Weather, Volume 24, Issue 9, September 2026.
Abstract This study presents a deep learning framework for real‐time prediction of post‐peak solar flare irradiance. The model targets the soft X‐ray band (0.1–0.8 nm) and three extreme ultraviolet (EUV) wavelength bands (9.0–9.9 nm, 13.0–13.9 nm, and 30.0–30.9 nm), and produces forecasts at 1‐min cadence for 3 hr after the flare peak.
Jeong‐Heon Kim, Junmu Youn, Sung‐Hong Park, Seungwoo Ahn, Young‐Sil Kwak, Yong‐Jae Moon, P. C. Chamberlin   +6 more
wiley   +1 more source

Observations of solar chromospheric heating at sub-arcsec spatial resolution

, 2018
A wide variety of phenomena such as gentle but persistent brightening, dynamic slender features (∼100 km), and compact (∼1″) ultraviolet (UV) bursts are associated with the heating of the solar chromosphere. High spatio-temporal resolution is required to
Chitta, L., L. P. Chitta, S. K. Solanki, H. N. Smitha, Solanki, S., Wiegelmann, T., T. Wiegelmann, Smitha, H.   +7 more
core   +1 more source

The ORCA‐TWIN qCMOS Experiment I. Science Case and Commissioning at Calar Alto Observatory

Astronomische Nachrichten, Volume 347, Issue 7, August 2026.
ABSTRACT We describe a pilot study to explore a new generation of fast and low noise CMOS image sensors for time domain astronomy, using two remote telescopes with a baseline of 1635 km. The experiment involves direct imaging with novel qCMOS image sensor technology that combines fast readout with sub‐electron readout noise.
Martin M. Roth, Paško Roje, Stella Vješnica, Stefan Cikota, Alex J. Brown, Mike Kretlow, Marco Azzaro, Santiago Reinhart, Jesús Aceituno, Harry Dawson, Carsten Denker, Torsten Enßlin, Stephan Geier, Thomas Granzer, Thomas Kupfer, Gianluca Li Causi, Samaya Nissanke, José Luis Ortiz, Fernando Pedichini, Katja Poppenhäger, Axel Schwope   +20 more
wiley   +1 more source