Interplanetary type III bursts and density fluctuations in the solar wind

0471610 - ÚFA 2017 AT eng A - Abstract
Krupař, Vratislav - Santolík, Ondřej - Souček, Jan - Krupařová, Oksana - Maksimovic, M. - Kontar, E. - Eastwood, J.
Interplanetary type III bursts and density fluctuations in the solar wind.
Abstract book of the 8th International Workshop on Planetary, Solar and Heliospheric Radio Emissions (PRE 8). Vienna: Austrian Academy of Sciences, 2016. s. 58.
[International Workshop on Planetary, Solar and Heliospheric Radio Emissions (PRE 8) /8./. 25.10.2016-27.10.2016, Seggauberg near Graz]
Institutional support: RVO:68378289
Keywords : solar radio emissions * plasma radiation * solar wind
Subject RIV: BL - Plasma and Gas Discharge Physics
http://pre8.oeaw.ac.at/files/Abstract_book.pdf

Type III bursts are generated by beams of fast electrons originated from reconnection sites of solar
flares. These beams propagate outwards from the Sun along open magnetic field lines in the corona
and in the interplanetary (IP) medium while exciting radio emission at the local plasma frequency fp
and/or its second harmonic 2 fp. We performed a statistical survey of 152 simple and isolated IP type
III bursts observed by STEREO/Waves instruments between May 2007 and February 2013. We
investigated their time-frequency profiles in order to derive decay times as a function of frequency.
Next, we performed Monte Carlo simulations to study a role of scattering due to random density
fluctuations on time-frequency profiles of radio emissions generated in the IP medium. Derived
decay times from observations and simulations were compared. We conclude that relative electron
density fluctuations ⟨δne⟩/ne at the outer scale of turbulence in the solar wind are 0.15 and 0.30
assuming the fundamental and harmonic emission, respectively.
Permanent Link: http://hdl.handle.net/11104/0268970