Results 41 to 50 of about 737 (157)

Worldwide character of the 1991 geomagnetic jerk [PDF]

Geophysical Research Letters, 1998
A recent examination of the geomagnetic element annual mean values for the European magnetic observatories, has shown the existence of a sudden change in the secular acceleration at about 1991. In this work the space time character of the 1991 impulse is investigated and its worldwide character is evidenced; an evaluation of the amplitude spatial ...
P. De Michelis, L. Cafarella, A. Meloni
openaire   +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

Four decades of European geomagnetic secular variation and acceleration

Annals of Geophysics, 2009
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Monika Korte, Giuliana Verbanac, Mioara Mioara Mandea   +2 more
doaj   +1 more source

The impact of geomagnetic spikes on the production rates of cosmogenic 14C and 10Be in the Earth's atmosphere [PDF]

, 2015
We seek corroborative evidence of the geomagnetic spikes detected in the Near East ca. 980 BC and 890 BC in the records of the past production rates of the cosmogenic nuclides 14C and 10Be.
Alexandre Fournier, Bard, Beer, Ben-Yosef, Cooke, Courtillot, Fraser-Smith, Gallet, Gallet, Gennady A. Kovaltsov, Heikkilä, Holme, Hulot, Ilya Usoskin, Kovaltsov, Kovaltsov, Licht, Livermore, Mandea, McCracken, Muscheler, Philip W. Livermore, Reimer, Roberts, Roth, Ruth, Shaar, Steinhilber, Usoskin, Usoskin, Usoskin, Usoskin, Wessel, Yiou, Yves Gallet   +34 more
core   +3 more sources

On the applicability of Backus' mantle filter theory [PDF]

, 2017
Geomagnetic jerks are sudden changes of trend in the geomagnetic secular variation. The Earth's mantle behaves as a filter for the jerks, causing a delayed and a smoothed signal at the Earth's surface. Backus' mantle filter theory relies on approximating
Amit, H., Jackson, A., Pinheiro, K. J.
core   +1 more source

Geomagnetic jerks from the Earth’s surface to the top of the core [PDF]

Earth, Planets and Space, 2007
Abstract Rapid changes in the magnetic field characterised by an abrupt change in the secular variation have been named “secular variation impulses” or “geomagnetic jerks”. Three of these events, around 1968, 1978 and 1990, occurred during the time-span covered by the comprehensive model CM4 (Sabaka et al., 2002, 2004).
Chambodut, Aude, Eymin, C., Mandea, Mioara   +2 more
openaire   +3 more sources

Multi‐Decadal Trends in the Low Latitude foF2 Driven by Secular Magnetic Variations

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract Long‐term ionospheric trends have been widely studied, but their origin and magnitude remain subjects of debate. This study quantifies the linear trend in the F2‐region critical frequency (foF2) and its local time dependence using observations from eight low‐latitude ionosonde stations.
D. Singh, S. R. Zhang, L. P. Goncharenko, I. S. Batista, A. J. Coster   +4 more
wiley   +1 more source

Finding the Magnetopause Standoff Distance Using Soft X‐Ray Images: Application for the SMILE Mission

Journal of Geophysical Research: Space Physics, Volume 131, Issue 2, February 2026.
Abstract Soft X‐rays are emitted in the magnetosheath and cusps because of solar wind charge exchange. The soft X‐ray Imager (SXI) on board Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) will measure these X‐rays. We developed a new method for finding the magnetopause standoff distance from simulations that reproduce the expected X‐ray ...
Andrey Samsonov, Jennifer Alyson Carter, Steven Sembay, Andrew Read, Colin Forsyth, Samuel Wharton, Philippe Escoubet   +6 more
wiley   +1 more source

SECULAR BEHAVIOR IN THE GEOMAGNETIC DATA AT PERMANENTOBSERVATORIES IN ARGENTINA

Anales (Asociación Física Argentina)
The secular variation of the geomagnetic field is the temporal variation that takes place in the field on time scales between few years to hundreds or thousands of years.
P. A. Sallago
doaj   +1 more source

Bayesian Inference of Local Paleosecular Variation From Sparse Paleomagnetic Data

Journal of Geophysical Research: Solid Earth, Volume 131, Issue 2, February 2026.
Abstract We introduce a novel Bayesian method to construct local paleosecular variation (PSV) curves. By modeling the geomagnetic field as a Gaussian process, global models can be incorporated as informative prior distributions. Because we use Hamiltonian Monte‐Carlo methods, complex age distributions resulting for example from radiocarbon calibration ...
M. A. Schanner, R. Meyer, L. V. de Groot
wiley   +1 more source