Results 71 to 80 of about 15,079 (225)

Detection of a Magnetic Discontinuity in the Upper Solar Chromosphere Associated with a Coronal Loop Brightening Observed by CLASP2.1

The Astrophysical Journal
We report the first detection of a magnetic discontinuity in the upper solar chromosphere associated with a coronal loop brightening. Our findings are based on novel observations obtained by the Chromospheric LAyer SpectroPolarimeter (CLASP2.1 ...
Donguk Song, Ryohko Ishikawa, David E. McKenzie, Javier Trujillo Bueno, Frédéric Auchère, Ryouhei Kano, Amy Winebarger, Takenori J. Okamoto, Laurel A. Rachmeler, Ken Kobayashi, Genevieve D. Vigil, Adam R. Kobelski, Christian Bethge, Eun-Kyung Lim, Luca Belluzzi, Ernest Alsina Ballester, Tanausú del Pino Alemán, Jiří Štěpán   +17 more
doaj   +1 more source

Solar Activity Impacts on Ionospheric Scintillation and Precise Point Positioning Based on Multi‐Year GNSS and Scintillation Observations

Space Weather, Volume 24, Issue 3, March 2026.
Abstract Solar activity induces ionospheric irregularities that degrade Global Navigation Satellite System (GNSS) performance through amplitude and phase scintillation. Although numerous studies have investigated event‐driven or regional responses, the nonlinear coupling between solar radiation, ionospheric scintillation, and precise point positioning (
Jincheng Li, Qi Liu, Xiaomin Luo, Manuel Hernández‐Pajares, Enric Monte‐Moreno, Guangxia Wang, Heng Yang, Chuanding Zhang, Li Yang, Yaoyao Liu   +9 more
wiley   +1 more source

Twisted flux tube emergence from the convection zone to the corona

, 2007
3D numerical simulations of a horizontal magnetic flux tube emergence with different twist are carried out in a computational domain spanning the upper layers of the convection zone to the lower corona.
Carlsson M., Dorch S. B. F., Fan Y., Hansteen V. H., Juan Martínez‐Sykora, Mats Carlsson, Moreno-Insertis F., Nordlund, Schussler M., Viggo Hansteen   +9 more
core   +1 more source

A New Method for Probabilistic Spatiotemporal Forecasts of Solar Soft X‐Ray “S‐Class” (>X10) Superflares

Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.
Abstract Solar superflares of S‐class (>X10 in soft X‐rays) pose extreme space weather hazards, yet their prediction remains a fundamental challenge owing to their rapid and transient natures and the limitations of conventional event‐based forecasts. We introduce for the first time, a probabilistic spatiotemporal framework designed to identify extended
V. M. Velasco Herrera, G. Velasco Herrera, W. Soon, A. Özgüç, N. Babynets, A. Tlatov, M. Švanda, S. Qiu, S. Baliunas, B. Kotan, G. González González, L. A. Bautista Flores, M. Pazos   +12 more
wiley   +1 more source

Bidirectional outflows as evidence of magnetic reconnection leading to a solar microflare

, 2016
Magnetic reconnection is a rapid energy release process that is believed to be responsible for flares on the Sun and stars. Nevertheless, such flare-related reconnection is mostly detected to occur in the corona, while there have been few studies ...
Cao, Wenda, Chen, Feng, Cheng, Xin, Ding, M. D., Fang, Cheng, Hong, Jie, Li, Ying, Yang, Kai   +7 more
core   +1 more source

Solar science with the Atacama Large Millimeter/submillimeter Array - A new view of our Sun [PDF]

, 2015
The Atacama Large Millimeter/submillimeter Array (ALMA) is a new powerful tool for observing the Sun at high spatial, temporal, and spectral resolution.
Alissandrakis, C. E., Antolin, P., Ayres, T., Barta, M., Bastian, T., Benz, A. O., Black, J. H., Brajsa, R., De Pontieu, B., Doyle, J. G., Fleck, B., Fleishman, G., Gary, D., Gunar, S., Hauschildt, P., Heinzel, P., Hudson, H., Karlicky, M., Kato, Y., Kontar, E. P., Labrosse, N., Loukitcheva, M., Ludwig, H. -G., Nakariakov, V. M., Nindos, A., Perez, E., Scullion, E., Selhorst, C. L., Shimojo, M., Solanki, S. K., Soler, R., Tiwari, S. K., van der Voort, L. Rouppe, Van Doorsselaere, T., Wedemeyer, S., White, S. M., Yagoubov, P., Zaqarashvili, T.   +37 more
core   +2 more sources

Space Weather Impact of Three Solar Flares Observed by the POEMAS Telescope at 45 and 90 GHz

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract Solar flares are often associated with coronal mass ejections (CMEs) that, when directed toward Earth, can disrupt the magnetosphere and impact space weather. In this study, we investigate three long‐duration solar flares observed in 2012 by the POlarization Emission of Millimeter Activity at the Sun (POEMAS) telescopes at 45 and 90 GHz.
Adriana Valio, Karla F. Lopez, José Luis Gamonal Valenzuela, Ruben M. Romero Ramírez, Dougas F. da Silva   +4 more
wiley   +1 more source

Propagating and Stationary Bright Knots in the Quiet Sun

The Astrophysical Journal Letters, 2022
The question of what heats the solar chromosphere and corona remains one of the most important puzzles in solar physics and astrophysics. Up to now, two mechanisms are considered to work in heating the chromosphere and corona: magnetic reconnection and ...
Jun Zhang, Yijun Hou, Yue Fang, Feng Chen, Ting Li, Xiaoli Yan, Tao Ding, Zhiping Song, Yongyuan Xiang, Zhong Liu   +9 more
doaj   +1 more source

The formation of IRIS diagnostics II. The formation of the Mg II h&k lines in the solar atmosphere

, 2013
NASA's Interface Region Imaging Spectrograph (IRIS) small explorer mission will study how the solar atmosphere is energized. IRIS contains an imaging spectrograph that covers the Mg II h&k lines as well as a slit-jaw imager centered at Mg II k ...
Carlsson, M., de Pontieu, B., Leenaarts, J., Pereira, T. M. D., Uitenbroek, H.   +4 more
core   +1 more source

Commission 11. (Chromospheric Phenomena.) [PDF]

Transactions of the International Astronomical Union, 1936
Le Président évoque la mémoire du Dr C. E. Saint John, décédé peu de temps avant le Congrès et qui, alors qu’il présidait la Commission groupant toutes les recherches de Physique solaire, portait un intérêt très vif aux travaux dont s’occupe maintenant la Commission n.Deux demandes de subventions ont été soumises à la Commission: l’une, de M.
L. D’Azambuja, H. W. Newton
openaire   +2 more sources