scholarly journals GEOTAIL observation of upstream ULF waves associated with lunar wake

2003 ◽  
Vol 55 (9) ◽  
pp. 569-580 ◽  
Author(s):  
Tomoko Nakagawa ◽  
Yoshinori Takahashi ◽  
Masahide Iizima
Keyword(s):  
Ulf Waves ◽  
Lunar Wake

scholarly journals Upstream ULF waves and energetic electrons associated with the lunar wake: Detection of precursor activity

1996 ◽  
Vol 23 (10) ◽  
pp. 1271-1274 ◽  
Author(s):  
W. M. Farrell ◽  
R. J. Fitzenreiter ◽  
C. J. Owen ◽  
J. B. Byrnes ◽  
R. P. Lepping ◽  
...  
Keyword(s):  
Ulf Waves ◽  
Energetic Electrons ◽  
Lunar Wake ◽  
Wake Detection ◽  
Precursor Activity

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 resolution observations of spectral width features associatedwith ULF wave signatures in artificial HF radar backscatter

2004 ◽  
Vol 22 (1) ◽  
pp. 169-182 ◽  
Author(s):  
D. M. Wright ◽  
T. K. Yeoman ◽  
L. J. Baddeley ◽  
J. A. Davies ◽  
R. S. Dhillon ◽  
...  
Keyword(s):  
High Resolution ◽  
Plasma Source ◽  
Spectral Width ◽  
Hf Radar ◽  
Mhd Waves ◽  
Small Scale ◽  
Ulf Waves ◽  
Source Population ◽  
Radar Backscatter ◽  
Field Lines

Abstract. The EISCAT high power heating facility at Tromsø, northern Norway, has been utilised to generate artificial radar backscatter in the fields of view of the CUTLASS HF radars. It has been demonstrated that this technique offers a means of making very accurate and high resolution observations of naturally occurring ULF waves. During such experiments, the usually narrow radar spectral widths associated with artificial irregularities increase at times when small scale-sized (high m-number) ULF waves are observed. Possible mechanisms by which these particle-driven high-m waves may modify the observed spectral widths have been investigated. The results are found to be consistent with Pc1 (ion-cyclotron) wave activity, causing aliasing of the radar spectra, in agreement with previous modelling work. The observations also support recent suggestions that Pc1 waves may be modulated by the action of longer period ULF standing waves, which are simultaneously detected on the magnetospheric field lines. Drifting ring current protons with energies of ∼ 10keV are indicated as a common plasma source population for both wave types. Key words. Magnetospheric physics (MHD waves and instabilities) – Space plasma physics (wave-particle interactions) – Ionosphere (active experiments)

Multisatellite studies of ULF waves

1988 ◽  
Vol 8 (9-10) ◽  
pp. 427-436 ◽  
Author(s):  
Kazue Takahashi
Keyword(s):  
Ulf Waves

scholarly journals Pitch angle diffusion of electrons at the boundary of the lunar wake

2005 ◽  
Vol 57 (9) ◽  
pp. 885-894 ◽  
Author(s):  
Tomoko Nakagawa ◽  
Masahide Iizima
Keyword(s):  
Pitch Angle ◽  
Lunar Wake

scholarly journals Multi-point Conjugate Observations of Dayside ULF Waves during an Extended Period of Radial IMF

2020 ◽  
Author(s):  
Xueling Shi ◽  
Michael D. Hartinger ◽  
J. B. H. Baker ◽  
John Michael Ruohoniemi ◽  
Dong Lin ◽  
...  
Keyword(s):  
Extended Period ◽  
Ulf Waves ◽  
Point Conjugate

scholarly journals Polarization Reversal of Low Frequency Magnetic Variation in the Lunar Wake

2021 ◽  
Author(s):  
Tomoko Nakagawa ◽  
Futoshi Takahashi ◽  
Yoshifumi Saito ◽  
Hisayoshi Shimizu
Keyword(s):  
Low Frequency ◽  
Polarization Reversal ◽  
Lunar Wake ◽  
Magnetic Variation

scholarly journals Modulation of chorus intensity by ULF waves deep in the inner magnetosphere

2016 ◽  
Vol 43 (18) ◽  
pp. 9444-9452 ◽  
Author(s):  
Zhiyang Xia ◽  
Lunjin Chen ◽  
Lei Dai ◽  
Seth G. Claudepierre ◽  
Anthony A. Chan ◽  
...  
Keyword(s):  
Ulf Waves ◽  
Inner Magnetosphere

ULF Wave Power During Geomagnetic Storms and Implications for Radial Diffusion Processes

2021 ◽  
Author(s):  
Jasmine Sandhu ◽  
Jonathan Rae ◽  
John Wygant ◽  
Aaron Breneman ◽  
Sheng Tian ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Diffusion Coefficients ◽  
Radiation Belt ◽  
Geomagnetic Storms ◽  
Radial Diffusion ◽  
Ulf Waves ◽  
Wave Power ◽  
Outer Radiation Belt ◽  
Large Variability ◽  
Ulf Wave

<p>Ultra Low Frequency (ULF) waves drive radial diffusion of radiation belt electrons, where this process contributes to and, at times, dominates energisation, loss, and large scale transport of the outer radiation belt. In this study we quantify the changes and variability in ULF wave power during geomagnetic storms, through a statistical analysis of Van Allen Probes data for the time period spanning 2012 – 2019. The results show that global wave power enhancements occur during the main phase, and continue into the recovery phase of storms. Local time asymmetries show sources of ULF wave power are both external solar wind driving as well as internal sources from coupling with ring current ions and substorms.</p><p>The statistical analysis demonstrates that storm time ULF waves are able to access lower L values compared to pre-storm conditions, with enhancements observed within L = 4. We assess how magnetospheric compressions and cold plasma distributions shape how ULF wave power propagates through the magnetosphere. Results show that the Earthward displacement of the magnetopause is a key factor in the low L enhancements. Furthermore, the presence of plasmaspheric plumes during geomagnetic storms plays a crucial role in trapping ULF wave power, and contributes significantly to large storm time enhancements in ULF wave power.</p><p>The results have clear implications for enhanced radial diffusion of the outer radiation belt during geomagnetic storms. Estimates of storm time radial diffusion coefficients are derived from the ULF wave power observations, and compared to existing empirical models of radial diffusion coefficients. We show that current Kp-parameterised models, such as the Ozeke et al. [2014] model, do not fully capture the large variability in storm time radial diffusion coefficients or the extent of enhancements in the magnetic field diffusion coefficients.</p>

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