The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2
by L. Harra et al*

2021-09-16 166 views

During encounter 2 of NASA’s PSP mission there was a large amount of radio activity and, in particular, a noise storm of frequent, small type III bursts from 31 March to 6 April 2019. Our aim is to investigate the source of these small and frequent bursts. We studied the behaviour of active region 12737, whose emergence and evolution coincides with the timing of the radio noise storm and determined the […]

Langmuir wave motion observed in the most intense radio sources in the sky
by H. Reid and E. Kontar

2021-08-31 290 views

The Sun routinely produces energetic electrons in its outer atmosphere that subsequently travel through interplanetary space. These electron beams generate Langmuir waves in the background plasma, producing type III radio bursts that are the brightest radio sources in the sky (Suzuki & Dulk, 1985). These solar radio bursts also provide a unique opportunity to understand particle acceleration and transport which is important for our prediction of extreme space weather events […]

Statistics of Low Frequency Cutoffs for Type III Radio Bursts Observed by Parker Solar Probe during Its Encounters 1–5 by Bing Ma et al

2021-06-08 262 views

Interplanetary (IP) type III radio bursts are deemed to generate in the interplanetary space because of their lower emission frequency ($0.01 – 10$ MHz) in terms of plasma emission. However, using the electron cyclotron maser emission (ECME), Wu et al. (2004) presented that IP type III radio bursts may generate in the low corona. The low frequency cutoffs is an important parameter to research the generation mechanism of type III […]

Parametric simulation studies on the wave propagation of solar radio emission: the source size, duration, and position by Zhang et al.*

2021-05-11 219 views

The imaging and spectroscopy observations of solar radio bursts can provide information on the non-thermal electrons associated with the transient energy release in the solar active region and the parameters of the background plasma. However,  the corona plasma is an inhomogeneous refractive media for solar radio waves. Propagation effects, namely the refraction and scattering of waves, can cause the deformation of the observed radio source, including the expansion of the […]

Electromagnetic Emission Produced by Three-wave Interactions in a Plasma with Continuously Injected Counterstreaming Electron Beams
by Vladimir Annenkov and Igor Timofeev

2021-01-19 205 views

Weakly turbulent processes of three-wave interactions between Langmuir and electromagnetic waves in plasma with unstable electron flows are believed to be the main cause of type II and III solar radio emissions. The narrow band of type II bursts requires assuming that this radiation is generated in some local regions of shock fronts traveling in the solar corona, where the specific conditions for the enhancement of electromagnetic emissions near the […]

An Explanation of Subsecond Time Evolution of Type III Solar Radio Burst Sources at Fundamental and Harmonic Frequencies
by X. Chen et al

2020-12-14 232 views

Recent studies (Kontar et al. 2017) of a Type III–IIIb burst observed by LOFAR (van Haarlem et al. 2013) indicated that the temporal variations in the positions and source sizes do not fit into the standard picture of type III solar radio bursts and require a better understanding of radio-wave transport. With the aim of explaining the observed properties of type III–IIIb solar radio bursts, we use radio-wave simulations of radio-wave […]

Radio echo in the turbulent corona and simulations of solar drift-pair radio bursts observed with LOFAR
by Kuznetsov et al

2020-08-18 277 views

Drift-pair bursts are a rare and mysterious type of fine spectral structures in the low-frequency domain of solar radio emission. First identified by Roberts (1958), they appear in the dynamic spectrum as two parallel frequency-drifting bright stripes separated in time; the trailing stripe seems to repeat the morphology of the leading one with a typical delay of ~1–2 s (see, e.g., Figure 1). Recent imaging spectroscopy observations with the LOw-Frequency […]

Observations of fragmented energy release during solar flare emission
by R. Ramesh et al.*

2020-07-28 348 views

Type III radio bursts from the Sun are signatures of energetic (∼1–100 keV) electrons, accelerated at the reconnection sites, propagating upward through the corona into the interplanetary medium along open magnetic field lines. The emission mechanism of the bursts is widely believed to be due to coherent plasma processes. The bursts are observed typically in the frequency range $\approx 1\,$GHz$ – 10\,$kHz, which corresponds to radial distance range between the […]

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