Results 21 to 30 of about 23,252 (283)
Localized polar cap flow enhancement tracing using airglow patches: Statistical properties, IMF dependence, and contribution to polar cap convection [PDF]
Journal of Geophysical Research: Space Physics, 2015 AbstractRecent radar observations have suggested that polar cap flows are highly structured and that localized flow enhancements can lead to nightside auroral disturbances. However, knowledge of these flows is limited to available echo regions. Utilizing wide spatial coverage by an all‐sky imager at Resolute Bay and simultaneous Super Dual Auroral ...
Ying Zou +7 more
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Polar Cap Patch Prediction in the Expanding Contracting Polar Cap Paradigm [PDF]
Space Weather, 2019 AbstractSpace weather can cause serious disturbances of global navigation satellite systems (GNSS) used for positioning and navigation purposes. This paper describes a new method to forecast space weather disturbances on GNSS at high latitudes, in which we describe the formation and propagation of polar cap patches and predict their arrival at the ...
A. Fæhn Follestad +4 more
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HF radar polar patch formation revisited: summer and winter variations in dayside plasma structuring [PDF]
Annales Geophysicae, 2002 Three intervals of polar patch formation, as observed by the CUTLASS Finland HF coherent radar, are presented. Simultaneous observations from a vertical ionosonde located at Longyearbyen on Svalbard, situated in the dayside convection throat region,
S. E. Milan +3 more
doaj +1 more source
Periodicities of polar cap patches [PDF]
Journal of Geophysical Research: Space Physics, 2013 A highly sensitive all‐sky electron multiplier charge‐coupled device airglow imager has been operative in Longyearbyen, Norway since October 2011. The imager captures 630.0 nm all‐sky images with an exposure time of 4 s, which is about 10 times shorter than that achieved by conventional cooled CCD imagers.
K. Hosokawa +3 more
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Multi-instrument observations of polar cap patches and traveling ionospheric disturbances generated by solar wind Alfvén waves coupling to the dayside magnetosphere [PDF]
Annales Geophysicae, 2022 During minor to moderate geomagnetic storms, caused by corotating interaction regions (CIRs) at the leading edge of high-speed streams (HSSs), solar wind Alfvén waves modulated the magnetic reconnection at the dayside magnetopause.
P. Prikryl +6 more
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Morphology of polar cap patch activity [PDF]
Radio Science, 1999 For the period July 1, 1989, to June 30, 1990, for high solar activity, ƒ0F2 data were recorded by the Digital Ionospheric Sounding Systems from two Qaanaaq and Sondrestromfjord; ionospheric UHF scintillation data were recorded from Thule; and airglow images were recorded from Qaanaaq.
B. S. Dandekar, T. W. Bullett
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Polar cap patches observed during the magnetic storm of November 2003: observations and modeling [PDF]
Annales Geophysicae, 2015 We present multi-instrumented measurements and multi-technique analysis of polar cap patches observed early during the recovery phase of the major magnetic storm of 20 November 2003 to investigate the origin of the polar cap patches. During this event,
C. E. Valladares +2 more
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Diurnal and seasonal occurrence of polar patches [PDF]
Annales Geophysicae, 1996 Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there is a broad maximum in occurrence centred about magnetic noon ...
A. S. Rodger, A. C. Graham
doaj +1 more source
Geophysical Research Letters, 2022 By using a database of 4,634 cold patches (high density and low electron temperature) and 4,700 hot patches (high density and high electron temperature) from Defense Meteorological Satellite Program F16 in 2005–2018 winter months (October–March), we ...
Duan Zhang +8 more
doaj +1 more source
Simultaneous two hemisphere observations of the presence of polar patches in the nightside ionosphere [PDF]
Annales Geophysicae, 1994 The presence of polar patches as observed simultaneously in the same magnetic meridian of opposite nightside ionospheres by coherent and incoherent scatter radars are described.
A. S. Rodger +5 more
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