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Spectral analysis of magnetohydrodynamic fluctuations near interplanetary schocks
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Goldstein, M. L. Acuna, M. H. Vinas, A. F. |
| Copyright Year | 1983 |
| Description | Evidence for two types of relatively large amplitude MHD waves upstream and downstream of quasi-parallel forward and reverse interplanetary shocks is presented. The first mode is an Alfven wave with frequencies (in the spacecraft frame) in the range of 0.025 to 0.07 Hz. This is a left-hand polarized mode and propagates within a few degrees of the ambient magnetic field. The second is a fast MHD mode with frequencies in the range of 0.025 to 0.17 Hz, right-hand polarization and propagating along the magnetic field. These waves are detected principally in association with quasi-parallel shock. The Alfven waves are found to have plasma rest frame frequencies in the range of 1.1 to 6.3 mHz with wavelengths in the order of 4.8 x 10 to the 8th power to 2.7 x 10 to the 9th power cm. Similarly, the fast MHD modes have rest frame frequencies in the range 1.6 to 26 mHz with typical wavelengths about 2.19 x 10 to the 8th power cm. The magnetic field power spectrum in the vicinity of these interplanetary shocks is much steeper than f to the -s/3 at high frequencies. The observed spectra have a high frequency dependence of f to the -2/5 to f to the -4. |
| File Size | 2998582 |
| Page Count | 43 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19840004976 |
| Archival Resource Key | ark:/13960/t7dr7pj04 |
| Language | English |
| Publisher Date | 1983-11-01 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics Wavelengths Polarization Waves Magnetic Fields Magnetohydrodynamic Waves Spectrum Analysis Ion Beams Ntrs Nasa Technical Reports ServerĀ (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |