Results 61 to 70 of about 1,055 (183)

Geomagnetic observatories threatened again

Eos, Transactions American Geophysical Union, 1987
In its fiscal year (FY) 1988 budget, the U.S. Geological Survey (USGS) is again proposing to close two geomagnetic observatories (Eos, February 10, 1987, p. 78). Reliable sources have indicated to us that one of the contemplated closings is of an Alaskan observatory.
L. J. Lanzerotti, A. D. Chave
openaire   +1 more source

ESA Swarm Satellites Plasma Density Products: Comparison and Validation Against Incoherent Scatter Radars Observations

Space Weather, Volume 24, Issue 8, August 2026.
Abstract The European Space Agency's Swarm mission has provided over a decade of continuous in situ measurements of the topside ionospheric plasma. With the release of various official plasma density products and the development of several calibration methods, selecting the most reliable data set has become an important issue for the scientific ...
Alessio Pignalberi, Artem Smirnov, Chao Xiong, Vladimir Truhlik, Roberta Forte, Michael Pezzopane, Vincenzo Ventriglia, Luca Spogli, Lucilla Alfonsi   +8 more
wiley   +1 more source

Variability of dB/dt in the African Sector During Solar Cycle 24—Implications for Geomagnetically Induced Currents

Space Weather, Volume 24, Issue 8, August 2026.
Abstract This paper quantitatively characterizes dB/dt peaks at four African equatorial‐ and low‐latitude stations, along latitudinal and local‐time gradients across different phases of selected geomagnetic storms. We investigate dB/dt response for intense geomagnetic storms, Dst ≤ −100 nT observed during solar cycle 24 over four stations in the ...
Wuraola E. Oyegunle, C. M. Ngwira, A. O. Akala, E. O. Oyeyemi, B. Olugbon, O. J. Oyedokun, P. O. Amaechi   +6 more
wiley   +1 more source

Fourteen years of geomagnetic daily variation at Mario Zucchelli Station (Antarctica)

Annals of Geophysics, 2007
During the 1986-87 austral summer a geomagnetic observatory was installed at the Italian Antarctic Base Mario Zucchelli Station. In the first three years continuous time variation monitoring and absolute measurements of the geomagnetic ...
A. Meloni, D. Di Mauro, S. Lepidi, L. Cafarella, L. Santarelli, P. Palangio   +5 more
doaj   +1 more source

Response of Topside Ionospheric Electron Density During Solar Flares Using 2014–2024 Swarm Satellite Measurements

Geophysical Research Letters, Volume 53, Issue 14, 28 July 2026.
Abstract This paper presents a global statistical investigation into the topside ionosphere electron density response to X‐class solar flares during geomagnetically quiet conditions (Kp ≤ $\mathit{\le }$ 2) using Swarm satellites (462–511 km) data from 2014 to 2024.
Kenny Palo Monontsi, John Bosco Habarulema, Alessio Pignalberi, Christopher Dzivhuluwani Ndiitwani   +3 more
wiley   +1 more source

Latitudinal Discrepancy Between Thermospheric Density and Temperature Associated With Neutral Composition Effect

Geophysical Research Letters, Volume 53, Issue 14, 28 July 2026.
Abstract In this study, multi‐source thermospheric observations and TIEGCM simulations were used to explore the latitudinal variations of thermospheric temperature and total mass density at equinoxes. At nighttime, temperature and density exhibit consistent latitudinal patterns, with higher values at high latitudes.
Zhongli Li, Xiaoli Luan, Jiuhou Lei, Dexin Ren   +3 more
wiley   +1 more source

Physics‐Embedded Deep Learning Reveals the Memory Effect of Ionospheric Electron Density in Response to Solar EUV Forcing

Geophysical Research Letters, Volume 53, Issue 14, 28 July 2026.
Abstract Precise characterization of the electron density profile is crucial for optimizing high frequency communications. Reconstruction models often assume an instantaneous ionospheric response to solar forcing or using time delays, neglecting the time‐integrated cumulative “memory effect” of plasma dynamics.
Hongwei Gong, Hanxian Fang, Die Duan, Chao Xiao, Jintai Li, Chenghao Li, Hongtao Huang, Ganming Ren, Chuyue Zhou, Han Wu   +9 more
wiley   +1 more source

The multi scenarios applicability of GNSS differential positioning technology in the remeasurement of observatory azimuth in China [PDF]

Geoscientific Instrumentation, Methods and Data Systems
The azimuth angle of geomagnetic observatory marks is crucial for ensuring the reliability of geomagnetic observation data, and its remeasurement constitutes a core task in observatory operations. The Geomagnetic Network of China comprises 46 geomagnetic
Y. He, Y. He, X. Zhao, X. Zhao, S. Zhang, Q. Li, F. Yang, S. He, P. Guo, J. Zhou   +9 more
doaj   +1 more source

Statistical Evaluation of a Foreshock Transient Model Using Ground‐Based ULF Wave Observations

Geophysical Research Letters, Volume 53, Issue 14, 28 July 2026.
Abstract Hot flow anomalies and foreshock bubbles are discontinuity–driven foreshock transients that generate significant geospace disturbances. A recently developed analytical model can predict their upstream perturbations. In this study, we further evaluate this model by comparing its predictions with geomagnetic disturbances measured by ground‐based
Terry Zixu Liu, Vassilis Angelopoulos, Hui Zhang, Ying‐Dong Jia, Siqi Zhao   +4 more
wiley   +1 more source

Effect of a huge crustal conductivity anomaly on the H-component of geomagnetic variations recorded in central South America

Earth, Planets and Space, 2017
We describe here an analysis of the H-component of the geomagnetic field recorded in several temporary stations operating simultaneously in the central–eastern region of Brazil during nighttime pulsation events in 1994 and the sudden commencement of the ...
Antonio L. Padilha, Livia R. Alves, Graziela B. D. Silva, Karen V. Espinosa   +3 more
doaj   +1 more source