scholarly journals Ground observations of high-latitude Pc3-4 ULF waves

2005 ◽  
Vol 110 (A4) ◽  
Author(s):  
T. A. Howard ◽  
F. W. Menk
Keyword(s):  
High Latitude ◽  
Ulf Waves

scholarly journals Long-Lasting Poloidal ULF Waves Observed by Multiple Satellites and High-Latitude SuperDARN Radars

2018 ◽  
Vol 123 (10) ◽  
pp. 8422-8438 ◽  
Author(s):  
X. Shi ◽  
J. B. H. Baker ◽  
J. M. Ruohoniemi ◽  
M. D. Hartinger ◽  
K. R. Murphy ◽  
...  
Keyword(s):  
High Latitude ◽  
Ulf Waves

scholarly journals High-latitude observations of ULF waves with large azimuthal wavenumbers

2000 ◽  
Vol 105 (A3) ◽  
pp. 5453-5462 ◽  
Author(s):  
T. K. Yeoman ◽  
D. M. Wright ◽  
P. J. Chapman ◽  
A. B. Stockton-Chalk
Keyword(s):  
High Latitude ◽  
Ulf Waves

scholarly journals High-latitude HF Doppler observations of ULF waves: 2. Waves with small spatial scale sizes

1999 ◽  
Vol 17 (7) ◽  
pp. 868-876 ◽  
Author(s):  
D. M. Wright ◽  
T. K. Yeoman
Keyword(s):  
High Latitude ◽  
Radar Data ◽  
Mhd Waves ◽  
Ulf Waves ◽  
Vhf Radar ◽  
Magnetic Signature ◽  
High Latitude Ionosphere ◽  
Field Lines ◽  
Ground Magnetic ◽  
The Waves

Abstract. The DOPE (Doppler Pulsation Experiment) HF Doppler sounder located near Tromsø, Norway (geographic: 69.6°N 19.2°E; L = 6.3) is deployed to observe signatures, in the high-latitude ionosphere, of magnetospheric ULF waves. A type of wave has been identified which exhibits no simultaneous ground magnetic signature. They can be subdivided into two classes which occur in the dawn and dusk local time sectors respectively. They generally have frequencies greater than the resonance fundamentals of local field lines. It is suggested that these may be the signatures of high-m ULF waves where the ground magnetic signature has been strongly attenuated as a result of the scale size of the waves. The dawn population demonstrate similarities to a type of magnetospheric wave known as giant (Pg) pulsations which tend to be resonant at higher harmonics on magnetic field lines. In contrast, the waves occurring in the dusk sector are believed to be related to the storm-time Pc5s previously reported in VHF radar data. Dst measurements support these observations by indicating that the dawn and dusk classes of waves occur respectively during geomagnetically quiet and more active intervals.Key words. Ionosphere (auroral ionosphere; ionosphere-magnetosphere interactions) · Magnetospheric physics (MHD waves and instabilities)

scholarly journals Cluster observations of ULF waves with pulsating electron beams above the high latitude dusk-side auroral region

2004 ◽  
Vol 31 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Morooka ◽  
M. André ◽  
J.-E. Wahlund ◽  
S. C. Buchert ◽  
A. N. Fazakerley ◽  
...  
Keyword(s):  
High Latitude ◽  
Electron Beams ◽  
Ulf Waves ◽  
Auroral Region

scholarly journals High-latitude HF Doppler observations of ULF waves. 1. Waves with large spatial scale sizes

1997 ◽  
Vol 15 (12) ◽  
pp. 1548-1556 ◽  
Author(s):  
D. M. Wright ◽  
T. K. Yeoman ◽  
P. J. Chapman
Keyword(s):  
Field Line ◽  
High Latitude ◽  
Vertical Component ◽  
Low Frequency ◽  
Mhd Waves ◽  
Ulf Waves ◽  
Large Spatial Scale ◽  
Field Line Resonances ◽  
Doppler Data ◽  
Magnetometer Data

Abstract. A quantitative study of observations of the ionospheric signatures of magnetospheric ultra low frequency (ULF) waves by a high-latitude (geographic: 69.6°N 19.2°E) high-frequency Doppler sounder has been undertaken. The signatures, which are clearly correlated with pulsations in ground magnetometer data, exhibit periods in the range 100–400 s and have azimuthal wave numbers in the range 3–8. They are interpreted here as local field line resonances. Phase information provided by O- and X-mode Doppler data support the view that these are associated with field line resonances having large azimuthal scale sizes. The relative phases and amplitudes of the signatures in the Doppler and ground magnetometer data are compared with a model for the generation of Doppler signatures from incident ULF waves. The outcome suggests that the dominant mechanism involved in producing the Doppler signature is the vertical component of an E × B bulk motion of the local plasma caused by the electric field perturbation of the ULF wave.Key words. Auroral ionosphere · Magnetosphere-ionosphere interactions · MHD waves and instabilities HF Doppler · ULF Waves

Sign in / Sign up

Export Citation Format

Share Document