Community of European Solar Radio Astronomers

Non-thermal energy release in the post-impulsive phase of the May 9, 2021 event by M. Zhang et al.

2026-03-17

The acceleration of charged particles is an ubiquitous phenomenon in solar flares. Non-thermal electrons are especially probed by their hard X-ray (HXR) and radio emissions. Most flare analyses concern the impulsive flare phase, where the X-ray signatures are the most intense (i.e., the time range between the start and peak time of the soft X-ray burst).The post-impulsive phase of eruptive flares with its signatures of destabilization and the eruption of […]

Classification of Type II and Type III Solar Radio Bursts Using Transfer Learning by H. le Roux et al.

2026-03-03

Solar radio bursts (SRBs) are some of the most interesting signatures of solar activity. Their correlation with large solar eruptions and well-documented disruption to technological infrastructure especially highlights their relevance (Temmer 2021; Li et al. 2024; Liang et al. 2024). As the volume of radio data grows, it becomes increasingly important to ensure that there are reliable automated methods for the classification of SRBs, especially if these methods can contribute […]

Plasma instability at the front of ejected electrons and Type III emission by V. Krasnoselskikh et al.

2026-02-17

Type III bursts are usually described as a two-step process: energetic electrons excite Langmuir waves, which are then converted into radio emission near the plasma frequency (Ginzburg & Zhelezniakov 1958). The recent discovery of Fundamental-Harmonic pairs by Parker Solar Probe (PSP) shows that many fundamental type III bursts are weak and composed of short, rapidly varying elements whose intensity rises quickly and then decays more slowly at a fixed frequency […]

Solar Radio Wide‐Band Spectroscopy and Imaging Facilities of the Chinese Meridian Project Phase II by Yihua Yan et al.

2026-02-03

Radioheliographs and wideband solar radio spectrographs are essential components of the Chinese Meridian Project (CMP)‐II (C. Wang et al., 2024) that aims to monitor the whole solar‐terrestrial chain of space weather events, from the lower solar atmosphere to near‐Earth space. This work introduce the CMP‐II radio instruments, including the MUSER‐L/I/H, the super‐wideband spectrographs of Mingantu and Chashan stations covering the wideband range of 30 MHz–15 GHz. The overall design, some […]

Tracing Ion-Scale Turbulence and Energy Cascade Rate from the Solar Corona to 1 au by E. P. Kontar et al.

2026-01-20

The solar corona and solar wind are turbulent plasma environments where energy transfer from large-scale magnetohydrodynamic (MHD) fluctuations to smaller kinetic scales is thought to play a critical role in coronal heating and solar wind acceleration. Despite decades of research, the properties of turbulence at ion scales, where dissipation occurs, remain poorly constrained due to limited observational data. Moreover, the precise mechanisms that heat the corona, and accelerate and heat […]

Signatures of Confined and Eruptive Solar Flares in Microwave Spectra by E. W. Cliver et al.

2026-01-06

Solar flares are generally divided into two classes: eruptive flares (with associated coronal mass ejections; CMEs) and confined flares that lack CMEs. Because eruptive flares are the principal source of major space weather effects at Earth, relatively little attention was paid to confined flares until the great sunspot group of October 2014, designated NOAA 12192, passed across the solar disk giving rise to 35 large flares (29 “M” SXR-class and […]

A Wide-Band High-Frequency Type-II Solar Radio Burst by Vasanth et al.

2025-12-23

Type-II radio bursts are usually observed below 400 MHz with slowly-drifting narrow fundamental and/or harmonic bands. Events with starting frequencies higher than 400 MHz are rarely reported (e.g., Pohjolainen et al. 2008). Such high-frequency Type-IIs may stem from the CME interaction with surrounding dense structures in the corona, such as streamers, ray-like or loop structure, or from sources in the lower corona. Figure. 1. Dynamic spectrum of the high-frequency wide-band […]

First Robust Detection of Linear Polarization from Metric Solar Emissions: Challenging Established Paradigms by S. Dey et al.

2025-12-09

Polarization measurements of solar radio emissions are key diagnostics of coronal plasma, magnetic fields, and propagation effects, and can provide additional constraints on the emission mechanisms. At meter wavelengths, circular polarization (CP) has long been exploited in solar radio studies, while linear polarization (LP) has been assumed to be absent. This view arose from the expectations that strong coronal Faraday rotation would completely depolarize LP within typical observational bandwidths and […]