Langmuir waves - CESRA: Community of European Solar Radio Astronomers

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

February 17, 2026

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 […]

Polarization Analysis of Type III Langmuir/Z-mode Waves with Coherent Magnetic Component Observations by Solar Orbiter by T. Formánek et al.

August 5, 2025

Type III solar radio bursts are generated by beams of energetic electrons propagating through interplanetary space. These electron beams, released from the Sun, travel along the Parker spiral and grow Langmuir waves through a kinetic instability in the electron velocity distribution function. The generated Langmuir waves subsequently undergo mode conversion, producing a radio emission at the plasma frequency or its harmonic. Langmuir waves are electrostatic waves generating the electric field […]

Flare Accelerated Electron Transport in Type III Solar Radio Bursts: large-scale transport and super-diffusive beam expansion by E. P. Kontar et al.

January 21, 2025

Solar flares, the most powerful magnetic explosions in our solar system, are often accompanied by intense bursts of radio emission known as type III solar radio bursts. These bursts provide valuable clues about the acceleration and transport of energetic electrons in the Sun’s atmosphere and beyond. Understanding these bursts is not only crucial for solar physics but also for predicting space weather events that can disrupt our technological infrastructure. A […]

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

August 15, 2023

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 […]

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

May 3, 2022

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 […]