Interplanetary magnetic field power spectra with frequencies from 2.4 x 10 to the-5th Hz to 470 Hz from HELIOS-observations during solar minimum conditions
Item
Title (Dublin Core)
en-US
Interplanetary magnetic field power spectra with frequencies from 2.4 x 10 to the-5th Hz to 470 Hz from HELIOS-observations during solar minimum conditions
Description (Dublin Core)
en-US
By using data from the Technical University of Braunschweig flux-gate and search-coil magnetometer experiments on board of Helios 2 we study the spectral properties of the interplanetary magnetic field over a frequency range from 2.4 x 10-5 Hz up to 470 Hz. Examples of power spectral density estimates at different heliocentric distances are shown as well as the change of the spectra during the progress of a high speed stream. A general feature of the spectra is that in a log-log spectral representation the steepness of the power spectral density estimates varies as a function of frequency. If we relate the spectral densities by a power law P ∼ f –α, the spectral index α increases with increasing frequency. At 1 AU α varies on average from 1.6 to 3.4 and at 0.3 AU from 1.0 to 3.4, the major changes in the spectral index occurring at low frequencies. In addition, just within the frequency gap between the two experiments, between 2Hz and 4.7 Hz, an inflexion point is inferred from the spectrum above and below this frequency range. This spectral feature can at least partly be attributed to the damping of the Alfven-mode waves near the proton and also α-particle cyclotron frequencies. The observed power spectra are compared with models of MHD turbulence and it is found that at least some of the properties of MHD turbulence fit the observations remarkably well.
ARK: https://n2t.net/ark:/88439/y063880
Permalink: https://geophysicsjournal.com/article/70
ARK: https://n2t.net/ark:/88439/y063880
Permalink: https://geophysicsjournal.com/article/70
Creator (Dublin Core)
Denskat, K.U.
Beinroth, H.J.
Neubauer, F.M.
Subject (Dublin Core)
en-US
Interplanetary magnetic field
en-US
Solar wind plasma
en-US
Hydromagnetic waves and turbulence
en-US
Space
Publisher (Dublin Core)
en-US
Journal of Geophysics
Date (Dublin Core)
1983-12-15
Type (Dublin Core)
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
en-US
Peer-reviewed Article
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
https://journal.geophysicsjournal.com/JofG/article/view/70
Source (Dublin Core)
en-US
Journal of Geophysics; Vol 54 No 1 (1984): Journal of Geophysics; 60-67
2643-2986
2643-9271
Language (Dublin Core)
eng
Relation (Dublin Core)
https://journal.geophysicsjournal.com/JofG/article/view/70/30