Results 51 to 60 of about 733 (165)

Detection of High‐Latitude Magnetic Reconnection Between the Northward Interplanetary Magnetic Field and a Closed Magnetic Field Wedge Linked to a Transpolar Arc

Geophysical Research Letters, Volume 52, Issue 24, 28 December 2025.
Abstract Transpolar arcs (TPAs) describe a subset of auroral emissions observed poleward of the Earth's main auroral ovals when the interplanetary magnetic field (IMF) is northward. These emissions are thought to align with a “wedge” of closed magnetic field lines extending to the high‐latitude boundary of the Earth's magnetosphere, where they are ...
Nawapat Kaweeyanun, Robert C. Fear, Betty S. Lanchester, Daniel K. Whiter, Imogen L. Gingell, Andrew N. Fazakerley, Iannis Dandouras, Stephen B. Mende, Larry J. Paxton   +8 more
wiley   +1 more source

The dynamics and excitation of torsional waves in geodynamo simulations [PDF]

, 2013
The predominant force balance in rapidly rotating planetary cores is between Coriolis, pressure, buoyancy and Lorentz forces. This magnetostrophic balance leads to a Taylor state where the spatially averaged azimuthal Lorentz force is compelled to vanish
Jones, Chris A., Teed, Robert J., Tobias, Steven M.   +2 more
core   +2 more sources

Geomagnetic Jerks: Rapid Core Field Variations and Core Dynamics

Space Science Reviews, 2010
The secular variation of the core field is generally characterized by smooth variations, sometimes interrupted by abrupt changes, named geomagnetic jerks. The origin of these events, observed and investigated for over three decades, is still not fully understood.
Mandea, M., Holme, R., Pais, A., Pinheiro, K., Jackson, A., Verbanac, G.   +5 more
openaire   +6 more sources

A global analysis of the 1991 geomagnetic jerk [PDF]

Geophysical Journal International, 2000
Summary A recent examination of the geomagnetic annual mean values for the European magnetic observatories has shown the existence of a sudden change in the secular acceleration in about 1991 (Cafarella & Meloni 1995; Macmillan 1996). Using first differences of the Y (east geomagnetic field component) mean values from 74 observatories, the worldwide
Paola De Michelis, Lili Cafarella, Antonio Meloni   +2 more
openaire   +1 more source

GRACE Detection of Transient Mass Redistributions During a Mineral Phase Transition in the Deep Mantle

Geophysical Research Letters, Volume 52, Issue 17, 16 September 2025.
Abstract The temporal evolution of the core‐mantle boundary (CMB) is of critical importance in elucidating the dynamic interactions between the fluid core and the solid mantle, but remains largely unknown. To investigate corresponding mass redistributions, we analyze GRACE satellite and Satellite Laser Ranging (SLR) measurements of the 2003–2015 space ...
Charlotte Gaugne Gouranton, Isabelle Panet, Marianne Greff‐Lefftz, Mioara Mandea, Séverine Rosat   +4 more
wiley   +1 more source

New Archeomagnetic Directional Records From Iron Age Southern Africa (ca. 425-1550 CE) and Implications for the South Atlantic Anomaly [PDF]

, 2018
The paucity of Southern Hemisphere archeomagnetic data limits the resolution of paleosecular variation models. At the same time, important changes in the modern and historical field, including the recent dipole decay, appear to originate in this region ...
Huffman T. N., Huffman T. N., Huffman T. N., John A. Tarduno, Main M., Main M., Michael Watkeys, Munyaradzi Manyanga, Phenyo C. Thebe, Richard K. Bono, Rory D. Cottrell, Thomas Huffman, Vincent J. Hare   +12 more
core   +1 more source

AKR Observations From All Local Times Indicate Substorm Activity

Journal of Geophysical Research: Space Physics, Volume 130, Issue 9, September 2025.
Abstract Auroral Kilometric Radiation (AKR) is known to present emission at lower frequencies near substorm onset, corresponding to activation of higher altitude sources along auroral magnetic field lines and acting as a proxy of the vertical distribution of acceleration processes during these events.
J. E. Waters, L. Lamy, J. Coxon, C. M. Jackman, C. J. Lao, C. Forsyth, A. R. Fogg   +6 more
wiley   +1 more source

Statistical Distribution of Dawnside Auroral Polarization Streams

Geophysical Research Letters, Volume 52, Issue 13, 16 July 2025.
Abstract Dawnside auroral polarization streams (DAPS) are fast eastward flows in the dawn convection cell of Earth's ionosphere. With a steep flow gradient near the interface between Region 1 and 2 currents and a peak poleward of it, DAPS were suggested to be responsible for instabilities and dramatic events in the magnetosphere‐ionosphere (M‐I) system.
Jiang Liu, Colin Forsyth, L. R. Lyons, Chih‐Ping Wang, Vassilis Angelopoulos, Andrei Runov, Sheng Tian, Yangyang Shen, Johnathan K. Burchill, S. Milan   +9 more
wiley   +1 more source

Automatic quality control for geomagnetic observatories and fast detection of geomagnetic jerks

, 2023
MOSFiT (Magnetic Observatories and Stations Filtering Tool) is a python package to visualize and filter data from magnetic observatories and magnetometer stations. The purpose of MOSFiT is to automatically isolate and analyze the secular variation (SV) information contained in geomagnetic observatories data.
Siqueira Da Silva, M., Pinheiro, K., Ohlert, A., Matzka, J.   +3 more
openaire   +2 more sources

Predictions of Equatorial Vertical Plasma Drift Using TEC Data and a Neural Network Model

Earth and Space Science, Volume 12, Issue 6, June 2025.
Abstract Vertical plasma drift, vz, plays a key role in the dynamics, morphology, and space weather effects of the equatorial and low latitude ionosphere. Modeling the drift has been an on‐going effort for climatology‐based prediction. To address daily prediction, the Vertical drIfts: Predicting Equatorial ionospheRic dynamics (VIPER) model has been ...
S. A. Reddy, X. Pi, C. Forsyth, A. Aruliah, A. Smith   +4 more
wiley   +1 more source