scholarly journals Rapid density fluctuations in the solar wind

2005 ◽  
Vol 23 (12) ◽  
pp. 3765-3773 ◽  
Author(s):  
P. J. Kellogg ◽  
T. S. Horbury

Abstract. Electron density fluctuations (up to 2.5 Hz) in the solar wind have been studied, using the EFW experiment on the Cluster spacecraft, which measures density through measurements of the biased probe potentials relative to the spacecraft. The density fluctuation spectra obtained from the EFW probe potential variations are compared to earlier, OGO 5, measurements of ion density fluctuations and ISEE measurements of electron density fluctuations, and are consistent with them. The electric fields corresponding to the electron density fluctuations are extremely small compared with what would be obtained if the electron fluctuations were not cancelled out by nearly equal ion density fluctuations. This is consistent with the nature of ion acoustic waves. In agreement with ISEE work, the fluctuations are proportional to the ambient density. Correlation with magnetic fluctuations is weak, essentially nonexistent during part of the period studied. This might be expected as magnetic fluctuations are known to be nearly incompressible, but even the correlation with fluctuations in the magnitude of B is very small. However, many structures which apparently are pressure balance structures are found. Pressure balance structures are the nearly perpendicular propagation limit of ion acoustic waves. As ion acoustic waves are strongly damped in plasmas like the solar wind at least if the plasma is taken as Maxwellian, it has always been a puzzle as to why they are found there. We speculate that these waves are created by mode conversion from magnetic fluctuations, and may represent part of the dissipation process for these.

2016 ◽  
Vol 23 (8) ◽  
pp. 082901 ◽  
Author(s):  
T. Sreeraj ◽  
S. V. Singh ◽  
G. S. Lakhina

1978 ◽  
Vol 83 (A1) ◽  
pp. 58-74 ◽  
Author(s):  
D. A. Gurnett ◽  
L. A. Frank

2018 ◽  
Vol 857 (2) ◽  
pp. 82 ◽  
Author(s):  
V. Krupar ◽  
M. Maksimovic ◽  
E. P. Kontar ◽  
A. Zaslavsky ◽  
O. Santolik ◽  
...  

1995 ◽  
Vol 54 (3) ◽  
pp. 295-308 ◽  
Author(s):  
S. K. El-Labany

The derivative expansion perturbation method is applied to investigate the modulation of nonlinear ion-acoustic waves in a weakly relativistic warm plasma. At the second order of perturbation theory, a nonlinear Schrödingertype equation for the complex amplitude of the perturbed ion density is obtained. The coefficients in this equation show that the condition of modulational stability is modified by the relativistic effect as well as by the finite ion temperature. The association between the small-wavenumber limit of the nonlinear Schrödinger-type equation and the oscillatory solution of the Korteweg-de Vries equation obtained by reductive perturbation theory is considered. Different limits are considered in order to compare with previous work.


1980 ◽  
Vol 85 (A10) ◽  
pp. 5162-5164 ◽  
Author(s):  
Paul M. Kintner ◽  
Michael C. Kelley

2021 ◽  
Vol 911 (2) ◽  
pp. 89
Author(s):  
F. S. Mozer ◽  
J. W. Bonnell ◽  
E. L. M. Hanson ◽  
L. C. Gasque ◽  
I. Y. Vasko

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