Results 51 to 60 of about 682 (184)

Structure of the solar chromosphere [PDF]

Proceedings of the International Astronomical Union, 2004
The chromosphere is an intriguing part of the Sun that has stubbornly resisted all attempts at a comprehensive description. Thus, observations carried out in different wavelength bands reveal very different, seemingly incompatible properties. Not surprisingly, a debate is raging between supporters of the classical picture of the chromosphere as a ...
openaire   +2 more sources

NOAA's National Centers for Environmental Information Space Weather Data Inventory Status

Space Weather, Volume 23, Issue 7, July 2025.
Abstract We present here an updated overview of the Space Weather data curated and/or generated, improved, archived, and disseminated by the Solar Terrestrial Physics (STP) Section of the National Centers for Environmental Information (NCEI) in the National Oceanic and Atmospheric Administration (NOAA).
Alessandra Abe Pacini, Laurel Rachmeler, Kimberly Baugh   +2 more
wiley   +1 more source

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

Evolutions of various solar indices around sunspot maximum and sunspot minimum years [PDF]

Annales Geophysicae, 2002
The smoothed monthly sunspot numbers showed that in many solar cycles, (a) during years around sunspot maxima, there was only one prominent maximum, but in some cycles there was a broad plateau. If the beginning and end of these are termed as first
R. P. Kane, R. P. Kane
doaj   +1 more source

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

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

Ionisation in the Solar Chromosphere [PDF]

Nature, 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

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

The Bright Rim Prominences according to 2.5D Radiative Transfer

The Astrophysical Journal Letters
Solar prominences observed close to the limb commonly include a bright feature that, from the perspective of the observer, runs along the interface between itself and the underlying chromosphere. Despite several idealized models being proposed to explain
Jack M. Jenkins, Christopher M. J. Osborne, Ye Qiu, Rony Keppens, Chuan Li   +4 more
doaj   +1 more source