Results 61 to 70 of about 1,023,827 (208)
Astronomy & Astrophysics, 2007 Context: Observations indicate that the `quiet' solar photosphere outside active regions contains considerable amounts of magnetic energy and magnetic flux, with mixed polarity on small scales. The origin of this flux is unclear. Aims: We test whether local dynamo action of the near-surface convection (granulation) can generate a significant ...
Vögler, A., Schüssler, M.
openaire +3 more sources
Journal of Geophysical Research: Space Physics, Volume 131, Issue 10, October 2026.Abstract Ionospheric currents and their associated magnetic perturbations are difficult to predict due to the high variability of their driving mechanisms. In addition, the 3D structure of the currents is challenging to unravel due to the lack of direct observations within the current flow region, particularly in the E $E$‐layer.
P. Alken +6 more
wiley +1 more source
Nighttime Westward Equatorial Electrojet Observed During the January 2026 Geomagnetic Storm
Journal of Geophysical Research: Space Physics, Volume 131, Issue 10, October 2026.Abstract The equatorial electrojet (EEJ) is a narrow band of zonal electric current flowing in the E‐region ionosphere within approximately ±2° $\pm 2{}^{\circ}$ latitude of the magnetic equator. At night, the EEJ is generally considered very weak because of low ionospheric conductivity.
Y. Yamazaki +26 more
wiley +1 more source
Where is the solar dynamo? [PDF]
Journal of Physics: Conference Series, 2013 In this paper I review results from recent global magnetohydrodynamical numerical simulations of solar convection, as a springboard to address the question "Where is the solar dynamo". I first describe and contrast similarities and differences in the large-scale flows and magnetic fields such simulations can produce, with emphasis on polarity reversals
openaire +1 more source
Annales Geophysicae, 1999 Two aspects of solar MHD are discussed in relation to the work of the MHD simulation group at KIS. Photospheric magneto-convection, the nonlinear interaction of magnetic field and convection in a strongly stratified, radiating fluid, is a key process ...
M. Schüssler, M. Schüssler
doaj +1 more source
Space Weather, Volume 24, Issue 10, October 2026.Abstract Enhanced small‐scale ionospheric irregularities during geomagnetic storms can disturb Global Navigation Satellite System (GNSS) carrier‐phase tracking and are associated with reduced stability of ambiguity‐fixed precise point positioning (PPP‐AR), but their impact on kinematic positioning remains insufficiently quantified.
Dongsheng Zhao +7 more
wiley +1 more source
Connecting mean-field theory with dynamo simulations
Living Reviews in Solar PhysicsMean-field dynamo theory, describing the evolution of large-scale magnetic fields, has been the mainstay of theoretical interpretation of magnetism in astrophysical objects such as the Sun for several decades.
Petri J. Käpylä
doaj +1 more source
Space Weather, Volume 24, Issue 10, October 2026.Abstract We present a multi‐instrument analysis of the ionospheric response to the intense geomagnetic storm of 12 November 2025 over the American sector, with emphasis on the longitudinally asymmetric deformation, latitudinal expansion, and zonal drift reversal of equatorial plasma bubbles (EPBs).
G. A. S. Picanço +15 more
wiley +1 more source
Space Weather, Volume 24, Issue 10, October 2026.Abstract Space weather events can significantly alter the ionospheric electron density, affecting signal transmission and navigation accuracy in satellite‐based systems. Consequently, there is an urgent need for reliable forecasting of the Thermosphere‐Ionosphere (TI) system.
J. Pereira +5 more
wiley +1 more source
Predicting Solar Cycle 24 With a Solar Dynamo Model
, 2007 Whether or not the upcoming cycle 24 of solar activity will be strong is being hotly debated. The solar cycle is produced by a complex dynamo mechanism. We model the last few solar cycles by “feeding‿ observational data of the Sun's polar magnetic field ...
Piyali Chatterjee +6 more
core +1 more source