Stereoscopic Observations of Solar Radio Emissions by the S/Waves Instrument onboard the STEREO Spacecraft

0381111 - ÚFA 2013 FR eng D - Thesis
Krupař, Vratislav
Stereoscopic Observations of Solar Radio Emissions by the S/Waves Instrument onboard the STEREO Spacecraft.
L’Observatoire de Paris - École Doctorale Astronomie et Astrophysique d’le-de-France, Charles University in Prague - Faculty of Mathematics and Physics. Defended: Paris. 18.09.2012. - Paris: L’Observatoire de Paris: Prague: Charles University in Prague, 2012. 139 s.
R&D Projects: GA AV ČR IAA301120601; GA ČR(CZ) GAP209/12/2394
Grant - others:GA MŠk(CZ) ME 842; AV ČR(CZ) M100420902; AV ČR(CZ) M100420904
Institutional support: RVO:68378289
Keywords : Solar radio emissions * Goniopolarimetric inversion
Subject RIV: BL - Plasma and Gas Discharge Physics

Type II radio bursts are associated with the propagation of Coronal Mass Ejections (CMEs) in the corona and interplanetary medium (IPM). A CME-driven shock energizes locally electrons which in return generate radio emissions near the shock. As the shock moves outward into lower density IPM, the emissions are generated at lower frequencies. The type II radio signature provides a complementary view of the CME which can be related to the STEREO coronagraph images and in situ measurements. Type III bursts arise from impulsively accelerated electrons streaming outward from the Sun on open field lines, often associated with CMEs. The type III radio signature can be therefore used to measure the density and interplanetary magnetic field (IMF) structure of the volume between the Sun and the Earth. Combining the S/WAVES observations from the two spacecraft will lead to three dimensional source location of radio emissions (triangulation) and stereoscopic measurements of their properties. More precisely stereoscopic direction finding measurements from both spacecraft with increasing viewing angles, made on large data sets, will allow derivation of statistical characteristics of the radio emission as a function of observing direction. The emission directivity, or beam pattern, together with the source size and frequency drift rate, yields information on the emission mechanism, the radiation mode and on the propagation medium. The S/WAVES investigation will allow extending these previous studies up to 16 MHz using the two identical receivers on Stereo. It should also allow studying for the first time the radio directivity pattern of the type II emission associated with interplanetary CME shocks.
Permanent Link: http://hdl.handle.net/11104/0211651