POWER SPECTRAL DENSITY OF FLUCTUATIONS OF BULK AND THERMAL SPEEDS IN THE SOLAR WIND

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10334272" target="_blank" >RIV/00216208:11320/16:10334272 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.3847/0004-637X/825/2/121" target="_blank" >http://dx.doi.org/10.3847/0004-637X/825/2/121</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/0004-637X/825/2/121" target="_blank" >10.3847/0004-637X/825/2/121</a>

Result language

angličtina

Original language name

POWER SPECTRAL DENSITY OF FLUCTUATIONS OF BULK AND THERMAL SPEEDS IN THE SOLAR WIND

Original language description

This paper analyzes solar wind power spectra of bulk and thermal speed fluctuations that are computed with a time resolution of 32 ms in the frequency range of 0.001-2 Hz. The analysis uses measurements of the Bright Monitor of the Solar Wind on board the Spektr-R spacecraft that are limited to 570 km s(-1) bulk speed. The statistics, based on more than 42,000 individual spectra, show that: (1) the spectra of bulk and thermal speeds can be fitted by two power-law segments; (2) despite their large variations, the parameters characterizing frequency spectrum fits computed on each particular time interval are very similar for both quantities; (3) the median slopes of the bulk and thermal speeds of the segment attributed to the MHD scale are -1.43 and -1.38, respectively, whereas they are -3.08 and -2.43 in the kinetic range; (4) the kinetic range slopes of bulk and thermal speed spectra become equal when either the ion density or magnetic field strength are high; (5) the break between MHD and kinetic scales seems to be controlled by the ion beta parameter; (6) the best scaling parameter for bulk and thermal speed variations is a sum of the inertial length and proton thermal gyroradius; and (7) the above conclusions can be applied to the density variations if the background magnetic field is very low.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BL - Plasma physics and discharge through gases

OECD FORD branch

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Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

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Volume of the periodical

825

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

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UT code for WoS article

000381940800039

EID of the result in the Scopus database

2-s2.0-84978476941