Source regions of the type II radio burst observed during a CME–CME interaction on 2013 May 22
by P. Mäkelä et al.*

2016-12-06 3,072 views

Occasionally the Sun ejects a pair of magnetized plasma clouds, called coronal mass ejections (CMEs), roughly into the same propagation direction in closely timed sequence. If the second CME is faster than the first one, the CMEs could either just slip through each other or they could collide and interact, when the following CME catches up the preceding one. The possibility of the CME-CME interaction was first suggested by Gopalswamy […]

Propagation of Coronal Mass Ejections: Aerodynamic Drag
by Nishtha Sachdeva and Prasad Subramanian

2016-10-04 954 views

Coronal Mass Ejections (CMEs) are hot, massive blobs of plasma and magnetic fields that erupt from the Sun, and are sometimes Earth-directed. Depending on their speed and mass these transients can strongly effect the space weather, causing geomagnetic storms and damage to space bound technologies. It is therefore imperative to understand the CME kinematics and propagation dynamics. Close to the Sun, CMEs are governed by Lorentz Forces, while they are […]

An Analysis of Interplanetary Solar Radio Emissions Associated with a Coronal Mass Ejection
by V. Krupar et al.*

2016-09-13 1,469 views

Type II and type III bursts are generated, via the plasma emission mechanism, when beams of suprathermal electrons interact with the ambient plasma generating radio emissions at the plasma frequency fp (the fundamental emission) or at its second harmonic 2fp (the harmonic emission) [see also previous CESRA highlights here and here]. As the electron beams propagate outward from the Sun, radio emissions are generated at progressively lower frequencies corresponding to […]

Radio emission and relativistic proton acceleration in the large solar particle event of 20 Jan 2005
by Karl-Ludwig Klein and Sophie Masson

2015-01-16 283 views

Energetic particle acceleration Enhanced fluxes of solar energetic particles (SEP) – so-called SEP events – result from processes of explosive energy conversion in the corona, notably flares and coronal mass ejections. The highest energies of solar energetic nucleons detected in space or through gamma-ray emission in the solar atmosphere are in the GeV range. Where and how the particles are accelerated is still controversial. The most debated candidate processes are […]

Synchrotron Radio Emission from a Fast Halo Coronal Mass Ejection
by Tim Bastian

2007-12-27 374 views

Coronal and interplanetary (IP) type II radio emissions are widely believed to result from the interaction of a super-Alfvenic shock with the coronal and/or the interplanetary medium, producing plasma radiation at the fundamental and/or harmonic of the electron plasma frequency. In the case of coronal type II radio bursts, the nature of the shock driver remains controversial: flare blast waves, flare ejecta, and coronal mass ejections (CMEs) have all been […]

Radio-quiet Fast and Wide Coronal Mass Ejections
by Nat Gopalswamy

2007-02-07 81 views

Radio-quiet coronal mass ejections (CMEs) are those with no detectable type II radio emission in the metric and decameter-hectometric (DH) wavelengths. (The CMEs may be associated with other types of radio emission such as type III bursts, see definitions for the different types of bursts or the diagram of burst classification). The radio-loud CMEs are those with identifiable type II burst in the DH domain from Wind/WAVES data, irrespective of […]

Combining radio and optical observations for coronal magnetic field determination
by Henry Aurass

2006-02-15 197 views

We present a method newly developed at the Astrophysikalisches Institut Potsdam (AIP) for determining the structure and the strength of coronal magnetic fields during the late phase of solar flares. Fiber bursts Fiber bursts are a spectral fine structure occuring in some type IV radio burst continua. Here we assume that the fiber bursts are excited by whistler waves and their interaction with nonthermal electrons trapped in a magnetic loop. […]

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