Results 71 to 80 of about 447 (185)

ITalian Geomagnetic Reference Field (ITGRF): update for 2000 and secular variation model up to 2005 by autoregressive forecasting

Annals of Geophysics, 2003
The updated version of the ITalian Geomagnetic Reference Field (ITGRF) for 2000.0 and its secular variation model up to 2005.0 are presented in this paper.
J. M. Torta, A. Meloni, G. Dominici, L. Gaya-Piqué, A. De Santis, R. Tozzi   +5 more
doaj   +1 more source

Ray Tracing Method in a General Non‐Dipole Magnetic Field

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract We present a new general mathematical formulation of the Eikonal equations for ray tracing, which can use any internal magnetic field model. The analytical and tractable expressions are conveniently based on a vector formalism, which is independent of any coordinate system.
P.‐L. Blelly, J.‐F. Ripoll, A. Dubois, R. B. Horne, A. Marchaudon   +4 more
wiley   +1 more source

Candidate geomagnetic field models for IGRF-14 and secular acceleration since 2020

Earth, Planets and Space
IGRF-14 is the fourteenth generation of the International Geomagnetic Reference Field (IGRF), a spherical harmonic model of Earth’s main magnetic field and its secular variation, developed through international collaboration under the auspices of the ...
Arnaud Chulliat, Manoj Nair, Sam Califf
doaj   +1 more source

Near‐Earth Cosmic Ray Modulation Index ϕ and Neutron Monitor Cutoff Rigidities at Hourly Cadence: Toward an Improved Monitoring of Solar‐Terrestrial Radiation Environment, Space Weather, and Space Climate

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract Cosmic rays (CRs) are energetic particles originating from galactic and extragalactic sources. When arriving into the solar system and the Sun's heliosphere, they are diverted and modulated by the magnetic activity of the Sun. This modulation can be quantified by the modulation parameter ϕ $\phi $ determined with the Force‐field approximation (
Pauli Väisänen, Nicholas Larsen, Sergey Koldobskiy, Markus Similä, David Pelosi, Miguel Orcinha   +5 more
wiley   +1 more source

Testing Geomagnetic Reference Field models for 1990-2000 with data from the Trelew Geomagnetic Observatory, Argentina [PDF]

Geofísica Internacional, 2003
Every five years a new International Geomagnetic Reference Field (IGRF) model is released and the secular variation for the previous period is updated, producing the definitive DGRF model.
Marta E. Ghidella, Jacqueline Köhn, Julio C. Gianibelli   +2 more
doaj  

Arase/LEPi Observations of Low‐Energy H+ and O+ Ion Fluxes in the Inner Magnetosphere: Implications for the Relationship Between Warm Plasma Cloak and Oxygen Torus

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract We investigated the spatial distributions and pitch‐angle distributions of 30–300 eV H+ and O+ ion fluxes using data obtained by the low‐energy particle experiments‐ion mass analyzer (LEPi) onboard the Arase satellite. A statistical analysis over 3.7 years reveals that the H+ ion flux is enhanced at L > 4 from the premidnight sector through ...
Masahito Nosé, Kazushi Asamura, Yoshizumi Miyoshi, Jih‐Hong Shue, Trunali Shah, Ayako Matsuoka, Mariko Teramoto, Kazuhiro Yamamoto, Atsushi Kumamoto, Fuminori Tsuchiya, Yoshiya Kasahara, Atsuki Shinbori, Iku Shinohara   +12 more
wiley   +1 more source

Fundamental Poloidal Wave Event Extending From Midnight to Dawn

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract Fundamental poloidal (P1) waves are a class of magnetospheric standing Alfvén waves characterized by field line oscillations in the meridional plane. P1 waves are infrequently excited in the ring current region and are believed to be the source of giant pulsations (Pgs) observed on the ground. Pgs are mostly detected on the morning side with a
Kazue Takahashi, Michael D. Hartinger, Kiyokazu Koga   +2 more
wiley   +1 more source

An Investigation into the Use of Satellite Data to Develop a Geomagnetic Secular Variation Model over Southern Africa

Data Science Journal, 2011
There is a need to develop secular variation (SV) models using satellite data as the use of ground data is not always possible. Ground data has many limitations including limited data points and lack of data over ocean areas that are not easily ...
E Nahayo, P B Kotzé, M J Alport
doaj   +1 more source

Improving Geomagnetic Perturbation Forecasts in the Southern Hemisphere via Kernel‐Based Encoding of Mirror Symmetry

Journal of Geophysical Research: Machine Learning and Computation, Volume 3, Issue 4, August 2026.
Abstract Accurate forecasting of geomagnetic perturbations is essential for assessing space weather risk of geomagnetic activities. Thanks to decades of magnetometer observations from world‐wide distributed networks and upstream solar wind observations at L1, data‐driven modeling of global geomagnetic perturbations has become increasingly feasible ...
Hongfan Chen, Gabor Toth, Yang Chen, Shasha Zou, Xun Huan   +4 more
wiley   +1 more source

Detecting geomagnetic field nonlinearities by bispectral analysis and a phase coupling nonlinear technique

Annals of Geophysics, 2002
The Earth's magnetic field varies over a wide range of characteristic times, say, from years to centuries, and more. In order to detect some nonlinear features of the geomagnetic field evolution we first apply a nonlinear spectral technique, i.e ...
A. De Santis, R. Tozzi
doaj   +1 more source