Results 81 to 90 of about 14,964 (204)

Robust Statistical Techniques for Operational Maintenance of the 10.7 cm Solar Radio Flux

Space Weather, Volume 23, Issue 5, May 2025.
Abstract The F10.7 solar radio flux is a critical quantity for operational space weather nowcasting and forecasting, where it is routinely used as a driver for coupled atmospheric models to estimate a variety of important quantities such as the neutral atmospheric density.
Daniel A. Brandt, Erick F. Vega, Brian J. Thelen   +2 more
wiley   +1 more source

Constraining the Systematics of (Acoustic) Wave Heating Estimates in the Solar Chromosphere

The Astrophysical Journal, 2023
Acoustic wave heating is believed to contribute significantly to the missing energy input required to maintain the solar chromosphere in its observed state.
Momchil E. Molnar, Kevin P. Reardon, Steven R. Cranmer, Adam F. Kowalski, Ivan Milić   +4 more
doaj   +1 more source

Observation of a short-lived pattern in the solar chromosphere [PDF]

, 2006
In this work we investigate the dynamic behavior of inter-network regions of the solar chromosphere. We observed the chromosphere of the quiet Sun using a narrow-band Lyot filter centered at the Ca II K 2v emission peak with a bandpass of 0.3A.
Carlsson, De Pontieu, F. Wöger, Janssen, Kneer, Leenaarts, Lites, Lites, Neckel, O. von der Lühe, Rutten, S. Wedemeyer-Böhm, Socas-Navarro, Vernazza, W. Schmidt, Wedemeyer   +15 more
core   +2 more sources

Quasi‐Periodic Pulsations in Ionospheric TEC Synchronized With Solar Flare EUV Emission

Journal of Geophysical Research: Space Physics, Volume 130, Issue 4, April 2025.
Abstract The extreme ultraviolet (EUV) and X‐ray radiation emitted during solar flares has been shown to significantly increase the electron density of the Earth's ionosphere. During flares, quasi‐periodic pulsations in X‐ray flux originating in the corona have previously been linked to subsequent pulsations in the Earth's ionospheric D‐region. Similar
Aisling N. O’Hare, Susanna Bekker, Laura A. Hayes, Ryan O. Milligan   +3 more
wiley   +1 more source

Multi‐Source Forecast of Solar Cycle Flare Activity Using the Novel Informer‐Based Models

Space Weather, Volume 23, Issue 4, April 2025.
Abstract Solar flares, the significant indicators of solar activity, have an impact on Earth's satellites and communication systems. Accurate prediction of solar flare events is crucial for mitigating these effects. In this work, we use multiple data sources, including Geostationary Operational Environmental Satellites soft X‐ray flare flux and the ...
Jie Cao, Tingting Xu, Linhua Deng, Miao Wan, Xinhua Zhao, Yang Peng, Xueliang Zhou, Wenhua Wang, Lidong Huang, Wencheng Wang, Lei Yang, Weihong Zhou   +11 more
wiley   +1 more source

Three-dimensional hydrodynamical CO5BOLD model atmospheres of red giant stars VI. First chromosphere model of a late-type giant

, 2017
Although observational data unequivocally point out to the presence of chromospheres in red giant stars, no attempts have been made so far to model them using 3D hydrodynamical model atmospheres.
Klevas, Jonas, Kucinskas, Arunas, Ludwig, Hans-Gunter, Wedemeyer, Sven   +3 more
core   +1 more source

First Global Machine Learning Model to Predict the Rate of TEC Index (ROTI) Response to X‐Class Solar Flares

Space Weather, Volume 23, Issue 3, March 2025.
Abstract Solar flares are bursts of electromagnetic radiation originating in the Sun's atmosphere. Solar flares cause a rapid increase in ionization in the ionosphere, resulting in radio signal interference. This paper aims to predict the ionospheric response to the solar flare of various characteristics in all latitudes around the dayside ionosphere ...
A. Mahmoudian, F. Ghorbali, M. Vazifehkhah Hafteh   +2 more
wiley   +1 more source

Self-absorption in the solar transition region

, 2015
Transient brightenings in the transition region of the Sun have been studied for decades and are usually related to magnetic reconnection. Recently, absorption features due to chromospheric lines have been identified in transition region emission lines ...
Barczynski, Krzysztof, Chen, Feng, He, Jiansen, Peter, Hardi, Tian, Hui, Tu, Chuanyi, Wang, Linghua, Xia, Lidong, Yan, Limei, Zhang, Lei   +9 more
core   +1 more source

Chromospheric dynamics [PDF]

Symposium - International Astronomical Union, 1996
This brief review advertises a breakthrough in solar dynamics: the identification of chromospheric Ca II K2V “grains” as manifestations of acoustic shocks. The successful numerical reproduction of the intricate spectral characteristics of K2V grain formation by Carlsson & Stein shows that the non-magnetic solar chromosphere is pervaded by outward ...
openaire   +2 more sources

First Observations of a Geomagnetic Superstorm With a Sub‐L1 Monitor

Space Weather, Volume 23, Issue 3, March 2025.
Abstract Forecasting the geomagnetic effects of solar coronal mass ejections (CMEs) is currently an unsolved problem. CMEs, responsible for the largest values of the north‐south component of the interplanetary magnetic field, are the key driver of intense and extreme geomagnetic activity.
E. Weiler, C. Möstl, E. E. Davies, A. M. Veronig, U. V. Amerstorfer, T. Amerstorfer, J. Le Louëdec, M. Bauer, N. Lugaz, V. Haberle, H. T. Rüdisser, S. Majumdar, M. Reiss   +12 more
wiley   +1 more source