Low Frequency Array (LOFAR)

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 […]

Magnetic Field Geometry and Anisotropic Scattering Effects to Explain Puzzling LOFAR Solar Radio Burst Observations by D. L. Clarkson et al.

February 4, 2025

Solar radio bursts are an indirect signature of accelerated electron beams from the solar atmosphere. These fast electrons generate Langmuir waves as they propagate through a decreasing plasma density and ultimately lead to the bright broadband radio emissions with a characteristic fast frequency drift in dynamic spectra. Density turbulence in the plasma can modulate this process, producing fine structures such as sub-second, narrowband striae and spikes. These fine structures may […]

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 […]

Anisotropic density turbulence variation from the low corona to 1 au as deduced from solar radio observations by E. Kontar et al.

November 30, 2023

Density turbulence in the solar corona and solar wind is evident via the properties of solar radio bursts; angular scattering-broadening of extra-solar radio sources observed through the solar atmosphere, and can be measured in-situ in the solar wind. A viable density turbulence model should simultaneously explain all three types of density fluctuation observations. Solar radio bursts (e.g. Type I, II, III) observed below ~1 GHz are produced predominantly via plasma […]

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

April 11, 2023

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 […]