Results 51 to 60 of about 452 (183)

Geomagnetic secular variation 1995–2000 [PDF]

Journal of Geophysical Research: Solid Earth, 2003
A study was done to determine the difficulty of obtaining a field model for 1995 using magnetic observations taken since that epoch. Ørsted vector data taken from 1999 to 2001 in conjunction with scalar data from all surface ship surveys and secular variation data from magnetic observatories taken since 1995 were utilized.
Joseph C. Cain, David T. Mozzoni, Bruce B. Ferguson, Olufunto Ajayi   +3 more
openaire   +1 more source

Assessing the Economic Benefits of Space Weather Mitigation Investment Decisions: Evidence From Aotearoa New Zealand

Space Weather, Volume 24, Issue 10, October 2026.
Abstract Space weather events pose a growing threat to modern economies, yet their macroeconomic consequences remain underexplored. This study presents the first dedicated economic assessment of geomagnetic storm impacts on Aotearoa New Zealand, quantifying potential gross domestic product (GDP) losses across seven conservative disruption and ...
Edward J. Oughton, Andrew Renton, Daniel H. Mac Manus, Dennies Bor, Craig J. Rodger   +4 more
wiley   +1 more source

The BGS candidate models for IGRF-13 with a retrospective analysis of IGRF-12 secular variation forecasts

Earth, Planets and Space, 2021
The three candidate models submitted by the British Geological Survey for the 13th generation International Geomagnetic Reference Field are described.
William J. Brown, Ciarán D. Beggan, Grace A. Cox, Susan Macmillan   +3 more
doaj   +1 more source

Scaling of the geomagnetic secular variation timescale

Geophysical Journal International
SUMMARY The ratio of the magnetic power spectrum and the secular variation spectrum measured at the Earth’s surface provides a timescale $\tau _{\rm sv}(l)$ as a function of spherical harmonic degree l. $\tau _{\rm sv}$ is often assumed to be representative of timescales related to the dynamo inside the outer core and its scaling with l ...
Yue-Kin Tsang, Chris A Jones
openaire   +3 more sources

The Size of Greater India: Estimates by Comparing the Apparent Polar Wander Paths of the Tethyan Himalaya and the Indian Craton

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 10, October 2026.
Abstract The northern extent of Greater India is a critical, yet highly debated, parameter for reconstructing the India‐Asia collision. Previous paleomagnetic estimates, including the fill‐the‐gap and fixed great circle approaches, yield widely varying results, spanning from ∼200 to ∼3,000 km. These large discrepancies stem principally from two primary
Xianwei Jiao, Suo Wang, Yong Zhao, Tongming Fang   +3 more
wiley   +1 more source

A New View of Long-Term Geomagnetic Field Secular Variation

Frontiers in Earth Science, 2018
This study carries out a statistical analysis of high-resolution PSV records for the last ~70 ka from three different regions of the Earth. We consider directional and intensity variability in each region on time scales of 103-105 years in order to ...
Steve P. Lund
doaj   +1 more source

Bulgarian Geomagnetic Reference Field (BulGRF) for 2015.0 and secular variation prediction model up to 2020 [PDF]

Annales Geophysicae, 2017
The Bulgarian Geomagnetic Reference Field (BulGRF) for 2015.0 epoch and its secular variation model prediction up to 2020.0 is produced and presented in this paper.
M. Metodiev, P. Trifonova
doaj   +1 more source

Coordinate Systems and Transforms in Space Physics: Terms, Definitions, Implementations, and Recommendations for Reproducibility

Journal of Geophysical Research: Space Physics, Volume 131, Issue 10, October 2026.
Abstract In space physics, acronyms for coordinate systems (e.g., GEI, GSM) are commonly used; however, differences in their definitions and implementations can prevent reproducibility. In this work, we compare definitions in online resources, software packages, and frequently cited journal articles and show that implementation differences can lead to ...
R. S. Weigel, A. Y. Shih, R. Ringuette, I. Christopher, S. M. Petrinec, S. Turner, R. M. Candey, G. K. Stephens, B. Cecconi   +8 more
wiley   +1 more source

Short-term prediction of geomagnetic secular variation with an echo state network

Earth, Planets and Space
A technique for predicting the secular variation (SV) of the geomagnetic field based on the echo state network (ESN) model is proposed. SV is controlled by the geodynamo process in the Earth’s outer core, and modeling its nonlinear behaviors can be ...
Shin’ya Nakano, Sho Sato, Hiroaki Toh
doaj   +1 more source

Geomagnetic Secular Variation Over and Near the Antarctic Continent

Antarctic Record, 1961
南極大陸近辺における地球磁場の永年変化は著しくはげしいことが,IGY南極観測の結果明らかになった.特に,昭和基地近傍はその変化量がはげしく,鉛直磁力の変化量は約2×10γ/年にも達する.第4図と第5図とを比較すれば,南半球,特に南極大陸近辺の地球磁場永年変化が北半球のそれに比していかに著しいものであるか一見して明らかであろう.特に昭和基地とHeard島の間は2800kmの距離であるにかかわらず,前者ではZ=181γ/年,後者ではZ=-98γ/年である.このきわめて顕著な永年変化局部異常は第6図に示す如く,
Takesi NAGATA
doaj   +1 more source