Density Fluctuations in the Solar Wind Based on Type III Radio Bursts Observed by Parker Solar Probe

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F20%3A00523156" target="_blank" >RIV/68378289:_____/20:00523156 - isvavai.cz</a>

Result on the web

<a href="https://iopscience.iop.org/article/10.3847/1538-4365/ab65bd/pdf" target="_blank" >https://iopscience.iop.org/article/10.3847/1538-4365/ab65bd/pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4365/ab65bd" target="_blank" >10.3847/1538-4365/ab65bd</a>

Result language

angličtina

Original language name

Density Fluctuations in the Solar Wind Based on Type III Radio Bursts Observed by Parker Solar Probe

Original language description

Radio waves are strongly scattered in the solar wind, so that their apparent sources seem to be considerably larger and shifted than the actual ones. Since the scattering depends on the spectrum of density turbulence, a better understanding of the radio wave propagation provides indirect information on the relative density fluctuations, $epsilon =langle delta nrangle /langle nrangle $, at the effective turbulence scale length. Here, we analyzed 30 type III bursts detected by Parker Solar Probe (PSP). For the first time, we retrieved type III burst decay times, ${tau }_{{rm{d}}}$, between 1 and 10 MHz thanks to an unparalleled temporal resolution of PSP. We observed a significant deviation in a power-law slope for frequencies above 1 MHz when compared to previous measurements below 1 MHz by the twin-spacecraft Solar TErrestrial RElations Observatory (STEREO) mission. We note that altitudes of radio bursts generated at 1 MHz roughly coincide with an expected location of the Alfvén point, where the solar wind becomes super-Alfvénic. By comparing PSP observations and Monte Carlo simulations, we predict relative density fluctuations, epsilon, at the effective turbulence scale length at radial distances between 2.5 and 14 ${R}_{odot }$ to range from 0.22 to 0.09. Finally, we calculated relative density fluctuations, epsilon, measured in situ by PSP at a radial distance from the Sun of 35.7 ${R}_{odot }$ during perihelion #1, and perihelion #2 to be 0.07 and 0.06, respectively. It is in a very good agreement with previous STEREO predictions ($epsilon =0.06mbox{--}0.07$) obtained by remote measurements of radio sources generated at this radial distance.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

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

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

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

Name of the periodical

Astrophysical Journal. Supplement Series

ISSN

1538-4365

e-ISSN

—

Volume of the periodical

246

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

10

Pages from-to

57

UT code for WoS article

000537499300006

EID of the result in the Scopus database

2-s2.0-85087206382