Journal of Geophysical Research: Space Physics, 2009 The specific entropy (s = p/ργ) and total entropy (S = p1/γV) of the plasma sheet during substorms are investigated with DMSP observations using a method that assumes ion isotropy (as also assumed in the derivation of S = p1/γV) and empirical magnetic field models that capture the expected characteristics of substorm phases.
Simon Wing, Jay R. Johnson
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Dual HF radar study of the subauroral polarization stream [PDF]
Annales Geophysicae, 2007 The dual HF radars comprising the Tasman International Geophysical Environment Radar (TIGER) system often observe localized high-velocity F-region plasma flows (≥1500 m/s) in the midnight sector (20:00–02:00 MLT) at magnetic latitudes as low as ...
R. A. Makarevich, P. L. Dyson
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Association of cusp energetic ions with geomagnetic storms and substorms [PDF]
Annales Geophysicae, 2012 Energetic ions observed in the cusp have been explained as a result of processes within the magnetosphere, but also proposed as a driver of some of those same processes. This study assesses potential connections between energetic ions observed in the
J. T. Niehof +3 more
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Prelude to THEMIS tail conjunction study [PDF]
Annales Geophysicae, 2007 A close conjunction of several satellites (LANL, GOES, Polar, Geotail, and Cluster) distributed from the geostationary altitude to about 16 RE downstream in the tail occurred during substorm activity as indicated by global auroral imaging and ground ...
A. T. Y. Lui +10 more
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Correlation between ground-based observations of substorm signatures and magnetotail dynamics [PDF]
Annales Geophysicae, 2005 We present a substorm event study using the four Cluster spacecraft in combination with ground-based instruments, in order to perform simultaneous observations in the ionosphere and magnetotail.
E. Borälv +12 more
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A substorm in midnight auroral precipitation [PDF]
Annales Geophysicae, 2003 DMSP F7 spacecraft observations for the whole of 1986 were used to construct the empirical model of the midnight auroral precipitation during a substorm.
V. G. Vorobjev +3 more
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SABRE observations of structured ionospheric flows during substorm expansion phase onset [PDF]
Annales Geophysicae, 1994 The irregularity velocity patterns observed by the SABRE coherent radar at substorm expansion phase onset, which is identified by magnetometer observations of Pi2 pulsations, are occasionally highly structured.
E. G. Bradshaw, M. Lester, T. B. Jones
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Statistical study of high-latitude plasma flow during magnetospheric substorms [PDF]
Annales Geophysicae, 2004 We have utilised the near-global imaging capabilities of the Northern Hemisphere SuperDARN radars, to perform a statistical superposed epoch analysis of high-latitude plasma flows during magnetospheric substorms.
G. Provan +3 more
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Statistical visualization of the Earth's magnetotail and the implied mechanism of substorm triggering based on superposed-epoch analysis of THEMIS data [PDF]
Annales Geophysicae, 2014 To investigate the physical mechanism responsible for substorm triggering, we performed a superposed-epoch analysis using plasma and magnetic-field data from THEMIS probes. Substorm onset timing was determined based on auroral breakups detected by all-
S. Machida +5 more
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Non-triggered auroral substorms and long-period (1–4 mHz) geomagnetic and auroral luminosity pulsations in the polar cap [PDF]
Annales Geophysicae, 2017 A study is undertaken into parameters of the polar auroral and geomagnetic pulsations in the frequency range 1–4 mHz (Pc5∕Pi3) during quiet geomagnetic intervals preceding auroral substorms and non-substorm background variations.
N. Yagova +12 more
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