density fluctuations

LOFAR imaging spectroscopy reveals spike-like repeating radio burst pairs in the solar corona by Suli Ma et al.

June 17, 2026

The solar atmosphere is a turbulent and magnetized environment, with the release of magnetic energy readily manifesting as emission across the electromagnetic spectrum. Solar radio emission dominates the radio sky, with the brightest solar radio bursts generated via the plasma emission process. The emission has a complex frequency-time structure with many features that are yet to be understood. Observations Using the LOw Frequency ARray (LOFAR) radio telescope (van Haarlem et […]

Multi-spacecraft Radio Observations Trace the Heliospheric Magnetic Field by D. L. Clarkson et al.

April 25, 2025

Solar flares accelerate energetic electrons that escape into interplanetary space, guided by the Parker spiral magnetic field, and are responsible for the generation of the interplanetary Type III solar radio bursts. With multiple spacecraft now in orbit around the Sun (see e.g. Musset et al 2021), we are in a unique position of observing the propagation of radio emission through the heliosphere from multiple vantage points. Recent study by Clarkson […]

The angular and frequency dependence of solar radio burst rise and decay times using multi-spacecraft observations by Nicolina Chrysaphi et al.

August 27, 2024

Density fluctuations populating the heliosphere interfere with propagating radio photons, altering their trajectories through frequency-dependent effects like scattering. Crucially, these density fluctuations are anisotropic, leading to anisotropic scattering and directional radio-wave propagation. This means that observers at different positions may obtain different estimations of radio properties. Such effects are particularly evident in solar radio bursts which are emitted through the plasma emission mechanism. It has been shown that detectors at […]

Energetics of compressive waves in the solar corona by Francesco Azzollini et al

July 2, 2024

Inelastic scattering off moving or oscillating density fluctuations leads to broadening of radio signals propagating in the solar corona and solar wind. Using an anisotropic density fluctuation model from the kinetic scattering theory for solar radio bursts, we deduce the plasma velocities (perpendicular to the line of sight) required to explain observations of spacecraft signal frequency broadening. The kinetic energy associated with these inferred bulk velocities cascades to smaller and […]

Morphology of solar type II bursts caused by shock propagation through turbulent and inhomogeneous coronal plasma by A. Koval et al

September 26, 2023

Type II solar bursts are radio signatures of shock waves in the solar corona driven by solar flares or coronal mass ejections. Therefore, these bursts present complex spectral morphologies in solar dynamic spectra. In particular, the radio emission lane may separate into two thinner bands that is known as band-splitting (Vršnak et al., 2002). “Fractured” type II bursts, exhibiting spectrally indented shapes in the form of bumps or breaks, are […]