Results 41 to 50 of about 1,371 (185)

Reconstruction of Two‐Dimensional Magnetohydrodynamic and Hall Magnetohydrodynamic Equilibria in Space Using Physics‐Informed Neural Networks

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 2, April 2026.
Abstract We present a novel data analysis technique based on physics‐informed neural networks (PINNs) to reconstruct two‐dimensional (2D) magnetohydrodynamic (MHD) and Hall MHD equilibria in a space plasma from in situ spacecraft measurements. Our method incorporates the steady‐state MHD or Hall MHD equations—a set of partial differential equations ...
Hiroshi Hasegawa, Eunjin Choi, Kyoung‐Joo Hwang, Kyunghwan Dokgo   +3 more
wiley   +1 more source

Investigation of Phase Shift and Travel Time of Acoustic Waves in the Lower Solar Atmosphere Using Multiheight Velocities

The Astrophysical Journal
We report and discuss the phase shift and phase travel time of low-frequency ( ν < 5.0 mHz) acoustic waves estimated within the photosphere and photosphere–chromosphere interface regions, utilizing multiheight velocities in the quiet Sun.
Hirdesh Kumar, Brajesh Kumar, Shibu K. Mathew, A. Raja Bayanna, S. P. Rajaguru   +4 more
doaj   +1 more source

Reconstructing Historical Solar Indices for Predicting Past Space Weather Events

Space Weather, Volume 24, Issue 4, April 2026.
Abstract Modeling and forecasting the near‐Earth space environment, specifically the thermosphere, is particularly important because it affects the motion of low‐Earth orbit objects through atmospheric drag. Solar indices such as F10.7, S10.7, M10.7, and Y10.7 are commonly used as inputs to ionospheric and thermospheric density models.
Poshan Belbase, Denny M. Oliveira, Theodosios Chatzistergos, Gangkai Poh, Eftyhia Zesta   +4 more
wiley   +1 more source

Post‐Processing Probabilistic Forecasts of the Solar Wind by Data Mining Similar Scenarios

Space Weather, Volume 24, Issue 4, April 2026.
Abstract The solar wind speed at Earth is one of the most important parameters regarding the effects of space weather on society. Thus far, most approaches for predicting the solar wind speed produce a single‐value time series without uncertainty, or utilize ensemble methods which require custom calibration development.
Daniel E. da Silva, Yash Parlikar, Shaela I. Jones, Charles N. Arge   +3 more
wiley   +1 more source

A High-resolution, Inversion-based Synoptic Study of Solar Granulation

The Astrophysical Journal
The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun’s surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well known.
James W. Crowley, Ivan Milić, Gianna Cauzzi, Kevin Reardon   +3 more
doaj   +1 more source

TURBULENT DIFFUSION IN THE PHOTOSPHERE AS DERIVED FROM PHOTOSPHERIC BRIGHT POINT MOTION

The Astrophysical Journal, 2011
On the basis of observations of solar granulation obtained with the New Solar Telescope (NST) of Big Bear Solar Observatory, we explored proper motion of bright points (BPs) in a quiet sun area, a coronal hole, and an active region plage. We automatically detected and traced bright points (BPs) and derived their mean-squared displacements as a function
ABRAMENKO V. I, CARBONE, Vincenzo, YURCHYSHYN V, GOODE P. R, STEIN R. F, LEPRETI, Fabio, CAPPARELLI V, VECCHIO A.   +7 more
openaire   +3 more sources

Small‐scale elemental abundance variations in Ryugu particles from touchdown 1

Meteoritics &Planetary Science, Volume 61, Issue 4, Page 580-599, April 2026.
Abstract Ryugu materials closely resemble CI chondrites' mineralogical, chemical, and isotopic compositions; yet minor but resolvable differences in certain elemental abundances are evident. In this study, the bulk chemical compositions of eight individual Ryugu particles (1.5–4.3 mg) from the first touchdown site (TD1) were determined using triple ...
Karina López García, Tetsuya Yokoyama, Ikshu Gautam, Makiko K. Haba, Tsuyoshi Iizuka, Nao Nakanishi, Ryota Fukai   +6 more
wiley   +1 more source

Searching for Rotational X‐Ray Modulation on TIC 277539431

Astronomische Nachrichten, Volume 347, Issue 3, March 2026.
ABSTRACT TIC 277539431, a fast rotating M7 dwarf, was detected to host the highest latitude flare to date at 81°$$ {81}^{{}^{\circ}} $$. Magnetic activity like stellar flares occurring at high latitude indicate occurrence of coronal loops at these latitudes on fully‐convective M dwarfs. In contrast, sunspots usually occur below 30°$$ {30}^{{}^{\circ}} $
Desmond Dsouza, Katja Poppenhäger, Ekaterina Ilin   +2 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

Periodic Density Structures Observed in Ulysses Data: First Results

Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.
Abstract Periodic density structures (PDSs) are advecting quasi‐periodic (periodicities between several minutes and several hours) density enhancements observed in the solar wind and corona. There is strong evidence that PDSs are formed at the Sun.
Brent M. Randol, Nicholeen Viall, Larry Kepko, Simone Di Matteo   +3 more
wiley   +1 more source