scholarly journals Determination of the dispersion of low frequency waves downstream of a quasiperpendicular collisionless shock

1997 ◽  
Vol 15 (2) ◽  
pp. 143-151 ◽  
Author(s):  
M. A. Balikhin ◽  
L. J. C. Woolliscroft ◽  
H. St. C. Alleyne ◽  
M. Dunlop ◽  
M. A. Gedalin
Keyword(s):  
Phase Velocity ◽  
Low Frequency ◽  
Field Measurements ◽  
Wave Mode ◽  
Collisionless Shock ◽  
Absolute Value ◽  
Magnetic Field Measurements ◽  
The Waves ◽  
Low Frequency Waves

Abstract. A method of wave mode determination, which was announced in Balikhin and Gedalin, is applied to AMPTE UKS and AMPTE IRM magnetic field measurements downstream of supercritical quasiperpendicular shock. The method is based on the fact that the relation between phase difference of the waves measured by two satellites, Doppler shift equation, the direction of the wave propagation are enough to obtain the dispersion equation of the observed waves. It is shown that the low frequency turbulence mainly consists of waves observed below 1 Hz with a linear dependence between the absolute value of wave vector |k| and the plasma frame wave frequency. The phase velocity of these waves is close to the phase velocity of intermediate waves Vint = Vacos(θ).

scholarly journals Computational Low-Frequency Electromagnetic Dosimetry Based on Magnetic Field Measurements

2018 ◽  
Vol 2 (4) ◽  
pp. 302-309 ◽  
Author(s):  
Alessandro Arduino ◽  
Oriano Bottauscio ◽  
Mario Chiampi ◽  
Ilkka Laakso ◽  
Luca Zilberti
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Field Measurements ◽  
Magnetic Field Measurements

Results of ultra-low-frequency magnetic field measurements during the Guam Earthquake of 8 August 1993

1996 ◽  
Vol 23 (3) ◽  
pp. 241-244 ◽  
Author(s):  
Masashi Hayakawa ◽  
Ryusuke Kawate ◽  
Oleg A. Molchanov ◽  
Kiyohumi Yumoto
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Field Measurements ◽  
Magnetic Field Measurements ◽  
Frequency Magnetic Field

scholarly journals Propagation of high frequency waves in the quiet solar atmosphere

2008 ◽  
pp. 87-99 ◽  
Author(s):  
A. Andic
Keyword(s):  
Solar Atmosphere ◽  
High Frequency ◽  
Low Frequency ◽  
Magnetic Structures ◽  
Partial Heating ◽  
Fabry Perot ◽  
High Frequency Waves ◽  
Propagation Of Waves ◽  
The Waves ◽  
Low Frequency Waves

High-frequency waves (5 mHz to 20 mHz) have previously been suggested as a source of energy accounting for partial heating of the quiet solar atmosphere. The dynamics of previously detected high-frequency waves is analyzed here. Image sequences were taken by using the German Vacuum Tower Telescope (VTT), Observatorio del Teide, Izana, Tenerife, with a Fabry-Perot spectrometer. The data were speckle reduced and analyzed with wavelets. Wavelet phase-difference analysis was performed to determine whether the waves propagate. We observed the propagation of waves in the frequency range 10 mHz to 13 mHz. We also observed propagation of low-frequency waves in the ranges where they are thought to be evanescent in the regions where magnetic structures are present.

scholarly journals The RPW Low Frequency Receiver (LFR) on Solar Orbiter: in-situ LF electric and magnetic field measurements of the solar wind expansion

2020 ◽  
Author(s):  
Thomas Chust ◽  
Olivier Le Contel ◽  
Matthieu Berthomier ◽  
Alessandro Retinò ◽  
Fouad Sahraoui ◽  
...  
Keyword(s):  
Solar Wind ◽  
Low Frequency ◽  
Field Measurements ◽  
Solar Wind Plasma ◽  
Wind Condition ◽  
The Sun ◽  
Nasa Mission ◽  
Magnetic Field Measurements ◽  
Electric And Magnetic Field

<p>Solar Orbiter (SO) is an ESA/NASA mission for exploring the Sun-Heliosphere connection which has been launched in February 2020. The Low Frequency Receiver (LFR) is one of the main subsystems of the Radio and Plasma Wave (RPW) experiment on SO. It is designed for characterizing the low frequency (~0.1Hz–10kHz) electromagnetic fields & waves which develop, propagate, interact, and dissipate in the solar wind plasma. In correlation with particle observations it will help to understand the heating and acceleration processes at work during its expansion. We will present the first LFR data gathered during the Near Earth Commissioning Phase, and will compare them with MMS data recorded in similar solar wind condition.</p>

scholarly journals Determination of wave vectors using the phase differencing method

2013 ◽  
Vol 31 (9) ◽  
pp. 1611-1617 ◽  
Author(s):  
S. N. Walker ◽  
I. Moiseenko
Keyword(s):  
Wave Packet ◽  
Correlation Length ◽  
Coherence Length ◽  
Low Frequency ◽  
Plasma Waves ◽  
Mhd Waves ◽  
Space Plasmas ◽  
The Waves ◽  
Theoretical Results

Abstract. Due to the collisionless nature of space plasmas, plasma waves play an important role in the redistribution of energy between the various particle populations in many regions of geospace. In order to fully comprehend such mechanisms it is necessary to characterise the nature of the waves present. This involves the determination of properties such as wave vector k. There are a number of methods used to calculate k based on the multipoint measurements that are now available. These methods rely on the fact that the same wave packet is simultaneously observed at two or more locations whose separation is small in comparison to the correlation length of the wave packet. This limitation restricts the analysis to low frequency (MHD) waves. In this paper we propose an extension to the phase differencing method to enable the correlation of measurements that were not made simultaneously but differ temporally by a number of wave periods. The method is illustrated using measurements of magnetosonic waves from the Cluster STAFF search coil magnetometer. It is shown that it is possible to identify wave packets whose coherence length is much less than the separation between the measurement locations. The resulting dispersion is found to agree with theoretical results.

Low-frequency magnetic field measurements near the epicenter of the Ms7.1 Loma Prieta Earthquake

1990 ◽  
Vol 17 (9) ◽  
pp. 1465-1468 ◽  
Author(s):  
A. C. Fraser-Smith ◽  
A. Bernardi ◽  
P. R. McGill ◽  
M. E. Ladd ◽  
R. A. Helliwell ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Field Measurements ◽  
Loma Prieta Earthquake ◽  
Magnetic Field Measurements ◽  
Frequency Magnetic Field ◽  
Loma Prieta
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