Results 71 to 80 of about 1,455,996 (195)

Eigen‐Swarm: Swarm's Thermospheric Mass Density Modeling via Eigen‐Decomposition

Space Weather, Volume 23, Issue 7, July 2025.
Abstract Precise thermospheric mass density (TMD) prediction is essential for satellite orbital tracking, reentry calculations, and upper atmospheric processes under varying solar and magnetospheric conditions. In this paper, we construct an empirical model of TMD at 450 km altitude with accelerometer‐derived (ACC) TMD observations from the Swarm‐C ...
Charles Owolabi, Hyunju Connor, Don Hampton, Denny M. Oliveira, Andres Calabia, V. Sai Gowtam, Eftyhia Zesta   +6 more
wiley   +1 more source

Calcium Bright Knots and the Formation of Chromospheric Anemone Jets on the Sun

The Astrophysical Journal Letters
Space-based observations show that the solar atmosphere from the solar chromosphere to the solar corona is filled with small-scale jets and is linked with small-scale explosions.
Kunwar Alkendra Pratap Singh, Keisuke Nishida, Kazunari Shibata   +2 more
doaj   +1 more source

Heating of the solar chromosphere by ionization pumping

The Astrophysical Journal, 1981
A new theory is proposed to explain the heating of the solar chromosphere, and possibly the corona, by the dissipation of hydrodynamic compression waves. The basis of the dissipative mechanism, here referred to as ionization pumping, is hysteresis caused by irreversible relaxation of the chromospheric medium to ionization equilibrium following pressure
openaire   +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

Solar Vortex Tubes. III. Vorticity and Energy Transport

The Astrophysical Journal
This study investigated the mechanisms of vorticity generation and the role of vortex tubes in plasma heating and energy transport. Vortex tubes were identified using the instantaneous vorticity deviation technique in the MURaM data set of a simulated ...
Suzana S. A. Silva, Gary Verth, Istvan Ballai, Erico L. Rempel, Sergiy Shelyag, Luiz A. C. A. Schiavo, Tiago F. P. Gomes, Viktor Fedun   +7 more
doaj   +1 more source

High frequency oscillations in the solar chromosphere and their connection with heating [PDF]

Proceedings of the International Astronomical Union, 2007
AbstractHigh frequency acoustic waves have been suggested as a source of mechanical heating in the quiet solar chromosphere. To investigate this, we have observed intensity oscillations of several lines in the frequency interval 1.64-70mHz using data from the VTT Tenerife and the Dunn Solar Telescope at the National Solar Observatory.
Aleksandra Andic, M. Mathioudakis, F. P. Keenan, D. B. Jess, D. S. Bloomfield   +4 more
openaire   +1 more source

Nowcasting Solar EUV Irradiance With Photospheric Magnetic Fields and the Mg II Index

Space Weather, Volume 22, Issue 4, April 2024.
Abstract A new method to nowcast spectral irradiance in extreme ultraviolet (EUV) and far ultraviolet (FUV) bands is presented here, utilizing only solar photospheric magnetograms and the Mg II index (i.e., the core‐to‐wing ratio). The EUV and FUV modeling outlined here is a direct extension of the SIFT (Solar Indices Forecasting Tool) model, based on ...
Kara L. Kniezewski, Samuel J. Schonfeld, Carl J. Henney   +2 more
wiley   +1 more source

Height-dependent Slow Magnetoacoustic Wave Amplitude and Energy Flux in Sunspot Atmospheres

The Astrophysical Journal
Slow magnetoacoustic waves (SMAWs) have been considered a possible candidate for chromospheric heating in the past. This study analyzed 20 active regions observed between 2012 and 2016 to examine the amplitude and energy flux variation of SMAWs in the ...
Y. Sanjay, S. Krishna Prasad, P. S. Rawat   +2 more
doaj   +1 more source

Probabilistic Short‐Term Solar Driver Forecasting With Neural Network Ensembles

Space Weather, Volume 22, Issue 3, March 2024.
Abstract Space weather indices are used to drive forecasts of thermosphere density, which directly affects objects in low‐Earth orbit (LEO) through atmospheric drag force. A set of proxies and indices (drivers), F10.7, S10.7, M10.7, and Y10.7 are used as inputs by the JB2008, (https://doi.org/10.2514/6.2008‐6438) thermosphere density model.
Joshua D. Daniell, Piyush M. Mehta
wiley   +1 more source

MHD simulations of coronal heating [PDF]

, 2015
The problem of heating the solar corona requires the conversion of magnetic energy into thermal energy. Presently, there are two promising mechanisms for heating the solar corona: wave heating and nanoflare heating.
Tam, Kuan V.
core   +2 more sources