Results 81 to 90 of about 4,523 (241)

Contemporaneous Appearances of Auroral Spiral and Transpolar Arc: Polar UVI Observations and Global MHD Simulations

open access: yesEarth and Space Science, Volume 13, Issue 6, June 2026.
Abstract A local vortex‐structured aurora and a large‐scale transpolar arc (TPA) were contemporaneously observed by the Polar ultraviolet imager (UVI) during the late recovery phase of a substorm, and the interplanetary magnetic field (IMF) BY and BZ were negative and negative‐to‐positive. The TPA grew along the dawnside auroral oval from the nightside
Motoharu Nowada   +4 more
wiley   +1 more source

Modulation of nightside polar patches by substorm activity [PDF]

open access: yes, 2009
Results are presented from a multi-instrument study showing the influence of geomagnetic substorm activity on the spatial distribution of the high-latitude ionospheric plasma. Incoherent scatter radar and radio tomography measurements on 12 December 2001
Moen, J   +7 more
core   +1 more source

Influence of Geomagnetically Induced Currents on Power Line Harmonic Radiation Observed at the Kannuslehto Ground‐Based Station

open access: yesJournal of Geophysical Research: Space Physics, Volume 131, Issue 6, June 2026.
Abstract This study investigates the properties of power line harmonic radiation (PLHR), a type of electromagnetic emission generated by electric power networks. In particular, we analyze how the PLHR intensity varies in relation to geomagnetically induced currents (GICs), quasi‐DC currents driven by rapid changes in the geomagnetic field during space ...
K. Drastichová   +3 more
wiley   +1 more source

Nonlinear Evolution of Auroral Fine Structures Through the Feedback Instability in a Dipole Field Configuration

open access: yesJournal of Geophysical Research: Space Physics, Volume 131, Issue 6, June 2026.
Abstract Nonlinear simulations of the feedback instability in the Alfvénic magnetosphere‐ionosphere (M‐I) coupling system have been carried out by means of the reduced magnetohydrodynamic (MHD) equations with spatially non‐uniform kinematic viscosity and resistivity, coupled with two‐fluid equations, in order to investigate auroral fine‐structure ...
T. Sakaki, T.‐H. Watanabe
wiley   +1 more source

Ionosphere‐Thermosphere Responses to the March 2023 Geomagnetic Storm Using Observations and TIEGCM Simulations Driven by Data Assimilated Aurora and Electric Fields

open access: yesJournal of Geophysical Research: Space Physics, Volume 131, Issue 6, June 2026.
Abstract We investigate Ionosphere‐Thermosphere (IT) responses to the March 2023 geomagnetic storm using GOLD and PFISR observations, along with TIEGCM simulations driven by data‐assimilated aurora and electric fields. A Lattice Kriging approach is implemented to assimilate auroral electron flux and characteristic energy from ground‐based (THEMIS/ASIs)
Prakash Poudel, Xian Lu
wiley   +1 more source

Study of the substorm: Part 2: Development of magnetosphere-ionosphere convection to the substorm

open access: yesAntarctic Record, 2014
It has been believed that the substorm is a manifestation of extraordinary plasma processes in the magnetosphere, such as instability, anomalous resistivity, and reconnection.
Takashi Tanaka
doaj   +1 more source

ERG observations of drift echoes during a unique period of the satellite mission

open access: yesEarth, Planets and Space, 2019
Substorm-associated electron injection, starting on Apr. 5, 2017, was observed by the ERG (Arase), GOES-15 and GOES-13 spacecraft. ERG successfully observed a clear and sufficient extent of manifestations of the dispersionless injection and the ...
Tzu-Fang Chang   +10 more
doaj   +1 more source

STUDY ON THE PARTICLE INJECTIONS DURING HILDCAA INTERVALS [PDF]

open access: yesJournal of Astronomy and Space Sciences, 2007
The relation between substorm occurrences and HILDCAA events has been an issue. We have studied the association of particle injections with substorm onsets during HILDCAA intervals for the first half of year 2003.
Hee-Jeong Kim
doaj   +1 more source

Gravity Wave Influences on MSTID Climatology Over CONUS: WACCM‐X Year‐Long Simulation and GNSS Long‐Term Observation

open access: yesJournal of Geophysical Research: Space Physics, Volume 131, Issue 6, June 2026.
Abstract Medium‐Scale Traveling Ionospheric Disturbances (MSTIDs) are prominent wave‐like structures in the ionosphere, with complex generation mechanisms involving both atmospheric gravity waves (GWs) and electrodynamic instabilities such as the Perkins instability (PI).
Jing Liu   +4 more
wiley   +1 more source

Interhemispheric comparison of spectral width boundary as observed by the SuperDARN radars [PDF]

open access: yes, 2003
International audiencePrevious studies have shown that dayside equatorward edge of coherent HF radar backscatter having broad Doppler spectral width is coincident with the equatorward edge of the cusp particle precipitation.
Milan, S. E.   +23 more
core   +1 more source

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