Results 51 to 60 of about 22,479 (200)
On Stellar Dynamo Processes and Differential Rotation [PDF]
, 2003 Many stars exhibit strong magnetic fields, some of which are thought to be of primordial origin and others a sign of magnetic dynamo processes. We briefly review the results of observational studies of solar-type stars seeking to evaluate the linkage ...
Brun, Allan Sacha
core +3 more sources
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
Mathematics, 2022 Estimating and predicting space weather is important to the space industry and space missions. The driver of space weather, especially near the Earth, is solar activity, the study of which is an important task.
Elena Popova +2 more
doaj +1 more source
Reversals of the solar magnetic dipole in the light of observational data and simple dynamo models
, 2014 Observations show that the photospheric solar magnetic dipole usually does not vanish during the reversal of the solar magnetic field, which occurs in each solar cycle. In contrast, mean-field solar dynamo models predict that the dipole field does become
Hoeksema, J. T. +3 more
core +1 more source
Constraining Electron‐Impact Ionization of O2 Through UV Aurora Observations at Ganymede
Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.Abstract While photoionization rates of Ganymede's O2 ${\mathrm{O}}_{2}$ dominated atmosphere are well constrained, the contribution of electron‐impact ionization is rather uncertain. Previous quantitative estimates have relied on assumptions about densities and energy distributions of precipitating electrons, or on rare spacecraft measurements that ...
Stefan Duling +5 more
wiley +1 more source
Helioseismic Properties of Dynamo Waves in the Variation of Solar Differential Rotation
The Astrophysical JournalSolar differential rotation exhibits a prominent feature: its cyclic variations over the solar cycle, referred to as zonal flows or torsional oscillations, are observed throughout the convection zone.
Krishnendu Mandal +2 more
doaj +1 more source
The Origin of Solar Activity in the Tachocline
, 2007 Solar active regions, produced by the emergence of tubes of strong magnetic field in the photosphere, are restricted to within 35 degrees of the solar equator.
Dikpati M. +7 more
core +2 more sources
Meridional Currents of the Equatorial Electrojet
Geophysical Research Letters, Volume 53, Issue 7, 16 April 2026.Abstract The equatorial electrojet (EEJ) is a prominent eastward geomagnetic current flowing at the dayside magnetic dip equator, peaking just before noon. Associated meridional currents also flow perpendicular to the main current, predicted through modeling and observed in rocket measurements.
X. G. V. M. Topacio, A. Yoshikawa
wiley +1 more source
Do Migrating Semidiurnal Tidal Winds From the Lower Atmosphere Control Thermospheric Winds?
Geophysical Research Letters, Volume 53, Issue 7, 16 April 2026.Abstract Lower atmospheric tides are important for driving the thermospheric and ionospheric structure. The effects of different lower atmospheric migrating semidiurnal tidal fields of neutral density, temperature, and winds on the thermospheric winds are investigated by using the global ionosphere‐thermosphere model with forcing of the tides at the ...
Chen Wu, Aaron J. Ridley
wiley +1 more source
Geophysical Research Letters, Volume 53, Issue 7, 16 April 2026.Abstract The threefold daytime electron density increases, along with strong poleward meridional winds exceeding 200 m/s were captured by Sanya Incoherent Scatter Radar (SYISR) during the geomagnetic storm of 12 November 2025. The great ionospheric enhancements were extending to mid‐latitudes over 40° observed by total electron content (TEC) from ...
Qi Jiang +7 more
wiley +1 more source