Results 31 to 40 of about 2,258 (224)

A comparison of ground-based hydroxyl airglow temperatures with SABER/TIMED measurements over 23° N, India [PDF]

Annales Geophysicae, 2017
Ground-based observations of OH (6, 2) Meinel band nightglow were carried out at Ranchi (23.3° N, 85.3° E), India, during January–March 2011, December 2011–May 2012 and December 2012–March 2013 using an all-sky imaging system.
N. Parihar, D. Singh, S. Gurubaran
doaj   +1 more source

Polytropic Index and Thermodynamic Behavior of the Central Plasma Sheet Near Lunar Distances

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract In addition to making near‐Earth observations, the THEMIS/ARTEMIS mission is uniquely positioned at lunar distance, in the deep magnetotail, reaching distances of 60 RE ${R}_{E}$ and further. This vantage point allows ARTEMIS to access the plasma sheet and measure entropy evolution across convective channels, plasma flow gradients ...
Ephrem Tesfaye Desta, R. D. Strauss, N. E. Engelbrecht   +2 more
wiley   +1 more source

Near‐Earth Solar Wind Speed of Fast Coronal Mass Ejections

Journal of Geophysical Research: Space Physics, Volume 131, Issue 8, August 2026.
Abstract Using solar wind and ground magnetometer data for solar cycles 23–25, extreme‐value power‐law models are developed that quantify relationships between near‐Earth solar wind speed and Sun‐to‐Earth transit times of interplanetary coronal mass ejections (ICMEs).
Jeffrey J. Love, Ian G. Richardson, E. Joshua Rigler, Kalevi Mursula   +3 more
wiley   +1 more source

Simultaneous OI 630 nm imaging observations of thermospheric gravity waves and associated revival of fossil depletions around midnight near the equatorial ionization anomaly (EIA) crest [PDF]

Annales Geophysicae
We report F-region airglow imaging of fossil plasma depletions around midnight that revived afresh under persisting thermospheric gravity wave (GW) activity. An all-sky imager recorded these events in OI 630 nm imaging over Ranchi (23.3° N, 85.3° E; mlat.
N. Parihar, S. Padincharapad, S. Padincharapad, A. K. Singh, P. Mahavarkar, A. P. Dimri   +5 more
doaj   +1 more source

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

A low-power data acquisition system for geomagnetic observatories and variometer stations [PDF]

Geoscientific Instrumentation, Methods and Data Systems, 2017
A modern geomagnetic observatory must provide data of high stability, continuity, and resolution. The INTERMAGNET network has therefore specified quantitative criteria to ensure a high quality standard of geomagnetic observatories.
A. Morschhauser, J. Haseloff, O. Bronkalla, C. Müller-Brettschneider, J. Matzka   +4 more
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

Solar flux dependence of coherence scales in scintillation patterns produced by ESF irregularities [PDF]

Annales Geophysicae, 2005
The coherence scale length, defined as the 50% decorrelation scale length along the magnetic east-west direction, in the ground scintillation pattern obtained at a dip equatorial location, due to scattering of VHF radio waves by equatorial spread F ...
B. Engavale, K. Jeeva, K. U. Nair, A. Bhattacharyya   +3 more
doaj   +1 more source

An Ionospheric Storm Scale Index Based on TEC: Comparative Analysis for China Region

Space Weather, Volume 24, Issue 8, August 2026.
Abstract Defining a standardized ionospheric storm scale is challenging given the ionosphere's inherent complexity and susceptibility to multiple driving factors. In this study, a novel ionospheric storm scale (ISS) index is developed based on statistical analysis of total electron content (TEC) data from 257 ground‐based GNSS stations across China ...
Shuangshuang Shi, Yunfei Shi, Kefei Zhang, Bingfeng Tan, Fucheng Song, Peng Sun, Yu Li, Yifan Liu, Shouxing Zhao   +8 more
wiley   +1 more source