Shock location and CME 3-D reconstruction of a solar type II radio burst with LOFAR
by P. Zucca et al.*

2018-10-30 285 views

Type II radio bursts are the result of shocks in the solar atmosphere and they can be observed ranging from sub-metric to kilometric wavelengths (~400 MHz to ~0.4 MHz). Coronal mass ejections initiate most of the metric type II (m-type II) bursts. The region of a CME responsible for driving the shock might be different for each event and has not yet been comprehensively identified. Multiple scenarios have been suggested, […]

Size distributions of solar proton events and their asso-ciated soft X-ray flares based on the maximum likelihood estimator
by E.W. Cliver and E. D’Huys

2018-09-18 310 views

It has been known for some time that the size distributions of solar radio bursts and soft X-ray (SXR) flares have steeper power-law slopes (~1.8) than those (~1.2) of solar energetic proton (SEP) events. Hudson (1978) suggested three possibilities for this difference: (1) proton flares are fundamentally different from ordinary flares; (2) proton flares represent the large end of the total energy distribution of ordinary flares; and (3) proton flare […]

An Extreme-ultraviolet Wave Generating Upward Secondary Waves in a Streamer-like Solar Structure
by Ruisheng Zheng et al.*

2018-08-07 305 views

Extreme-ultraviolet (EUV) waves are spectacular horizontally propagating disturbances in the low solar corona. If an EUV wave encounters an ambient coronal structure it may trigger another horizontal wave, which is always named a ‘secondary wave’ (SW). We present the first example of upward SWs in a streamer-like structure, a bright loop-like structure developing over an active region, after the passing of an EUV wave. The EUV wave was associated with […]

Long-lasting injection of solar energetic electrons into the heliosphere
by N. Dresing et al.

2018-07-24 265 views

The solar energetic particle (SEP) event from 26 Dec 2013 was a so-called widespread event observed by multiple spacecraft. The two STEREO and one close to Earth spacecraft spanned a total longitudinal angle of 210 degrees at that time. Together with the 25 Feb 2014 (Lario et al., 2016, Klassen et al., 2016) this is the widest event ever observed with the STEREO spacecraft. Unusually long-lasting SEP anisotropies together with […]

New evidence for a coronal mass ejection driven fast drifting type II radio burst
by K. Anshu et al.

2018-04-03 611 views

Type II solar radio bursts are considered to originate from plasma waves excited by magnetohydrodynamic (MHD) shocks and converted into radio waves at the local plasma frequency and its harmonics. Type II radio bursts are mostly associated with coronal mass ejections (CMEs) and flares Nindos et al. (2008). We studied a seldom occurring high frequency type II burst on 4th Novemeber 2015, which had both fundamental and harmonic components. The […]

The statistical relationship between global EUV waves and other solar phenomena
by D. Long et al.*

2018-01-23 410 views

Solar eruptions are associated with a variety of different phenomena, including solar flares, coronal mass ejections, Type II radio bursts, solar energetic particles and global coronal EUV waves (commonly known as “EIT waves”, e.g., Warmuth, 2015). However, the relationship between global waves and these other phenomena is not well defined. Although global waves have traditionally been studied using single event case studies, several statistical studies have been performed, with Thompson […]

Estimation of a CME magnetic field strength using observations of gyrosynchrotron radiation
by E. P. Carley et al.*

2018-01-09 731 views

Despite many years of study, the dominant driver and energy source of coronal mass ejections (CMEs) is still under investigation. Observational studies have indicated that magnetic energy represents the largest part of the total energy budget of the eruption (Emslie et al., 2012, Carley et al., 2012). However, despite having such a dominant influence on CME dynamics, little is known about CME magnetic field. This is due to the scarcity […]

Propagation and Interaction Properties of Successive Coronal Mass Ejections in Relation to a Complex Type II Radio Burst
by Y. D. Liu et al.*

2017-12-19 740 views

Quantifying how coronal mass ejections (CMEs), particularly fast ones, propagate from the Sun to the Earth is an overarching issue in CME research and space weather forecasting. A typical fast CME would finish its major deceleration well before reaching 1 AU (Liu et al. 2013). The actual situation of CME Sun-to-Earth propagation, however, may involve interactions with the highly structured solar wind including other CMEs. Interactions involving more than two […]

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