A possible new scenario for widespread solar energetic particle events by Nina Dresing et al.

2023-09-12 0 views

A long-standing problem in solar energetic particle (SEP) studies is to pinpoint their source regions at the Sun. Potential contributions by both the flare and CME-driven shocks complicate the analysis. A certain type of SEP events shows very wide particle spreads up to all around the Sun. The mechanisms proposed so far to generate these widespread events are a very wide SEP injection region, likely a shock, or strong perpendicular […]

Solar electron beam velocities that grow Langmuir waves in the inner heliosphere by C. Y. Lorfing et al.

2023-08-15 0 views

Solar accelerated electron beams interact with the background plasma of the solar wind to locally generate Langmuir waves and subsequently produce radio emission (Ginzburg and Zhelezniakov 1958). Numerous observations at different distances from the Sun by spacecrafts like Solar Orbiter (0.5AU) and ACE (1AU) show different energy ranges of electrons interacting with the plasma to produce Langmuir oscillations. At 0.5AU, non-thermal electrons in the deca-keV range arrive co-temporal to the […]

Solar Radio Spikes and Type IIIb Striae Manifestations Triggered by a Coronal Mass Ejection by Clarkson et al

2023-04-11 257 views

Radio bursts are frequently emitted in the outer solar corona due to the acceleration of energetic electrons in solar flares and coronal mass ejections (CME). The shortest observed bursts are radio spikes, which have narrow spectral widths and are emitted over decades in frequency. Despite being studied for many years, imaging observations are sparse and restricted to localisation of the emission at decimetre frequencies (e.g. Benz, 2002). Recently, LOw Frequency […]

Temporal and Spatial Association Between Microwaves and Type III Bursts in the Upper Corona by Altyntsev et al.

2023-03-28 158 views

One important task connected with the corona heating problem is exploring the physical mechanisms that produce, accelerate, and transport energetic particles in the upper corona. The magnetic connectivity between the sources of meter emission in the upper corona and electron acceleration sites in low corona are studied using the temporal correlation between hard X-ray (HXR) bursts and type III emission (Kane 1972; Aschwanden et al. 1995; Reid & Vilmer 2017). […]

The frequency ratio and time delay of fundamental and harmonic components in solar radio bursts by X. Chen et al

2023-02-28 247 views

Solar radio bursts generated through the plasma emission mechanism produce radiation near the local plasma frequency (fundamental emission, hereafter, F) and double the plasma frequency (harmonic, hereafter, H). While the theoretical ratio of these two frequencies is close to 2, simultaneous observations give ratios ranging from 1.6 to 2, suggesting either a ratio different from 2, a delay of the F emission, or both. Observations suggest that a delayed F […]

Solar radio bursts associated with in situ detected energetic electrons in solar cycles 23 and 24
by R. Miteva et al.*

2022-07-05 120 views

We present a short overview on the results from the first association analysis between in situ observed solar energetic electrons at 1 AU using the ACE/EPAM instrument (Samwel and Miteva, 2021) and radio bursts of type II, III and IV. The statistical analysis is performed over the last two solar cycles (SCs), 23 and 24 (1997-2019). All previous research has focused on energetic protons, whereas we aimed to compare in […]

Trieste CALLISTO Station Setup and Observations of  Solar Radio Bursts
by A. Marassi and C. Monstein

2022-06-21 179 views

A solar radio burst (SRB) is the intense solar radio emission often related to a solar flare and one of the possibly extreme space weather events which may affect Earth’s ionosphere and signal propagation, wireless communication, power grids and navigation systems. If an SRB occurs with the enhancement in L band radio flux, it could influence the Global Navigation Satellite Systems (GNSS) signals through direct radio wave interferences. The major […]

Langmuir-Slow Extraordinary Mode Magnetic Signature Observations with Parker Solar Probe
by A. Larosa et al

2022-05-03 142 views

Langmuir-Slow extraordinary mode (L-SE) waves have been routinely observed in the Solar wind and in Earth’s electron foreshock since the early age of the space exploration. They are intimately connected to the plasma emission mechanism for the type III and type II radio emissions. In fact, the generally accepted scenario is that L-SE waves are mode-converted to freely propagating electromagnetic emission at the plasma frequency. However,  the details of the […]

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