Radio Emissions from Bolides
Masters Thesis Presentation by Patrick Oppel
Tid: Fr 2021-06-11 kl 09.00 - 10.15
Föreläsare: Patrick Oppel
It is well understood that Type II radio bursts from the Sun and solar wind are due to shocks moving through the coronal and interplanetary plasma, accelerating electrons and producing Langmuir waves and radio emissions. Recently the Long Wavelength Array (LWA) in the USA observed radio waves from meteors and other bolides entering the ionosphere and atmosphere. Here we predict the radio emissions associated with the shock ahead of such bolides, which can include large man-made objects such as re-entry vehicles and space stations (including the International Space Station), moving through the ionosphere and upper atmosphere of Earth. Specifically, based on an existing theory for type II solar radio bursts, we calculate the electron distributions, the Langmuir waves they drive, and the radio emissions produced by specific nonlinear wave-wave processes. We also generalise the theory to include linear mode conversion of Langmuir waves into radio emissions at density gradients.