The diagnostic power of heliospheric radio emissions

Radio emissions excited by semi-relativistic electrons that are accelerated into the heliosphere by solar flares and CME-driven shocks are abundant, intense, and observed across various solar longitudes. We have shown that radio photons are highly-susceptible to anisotropic scattering off small-scale heliospheric density fluctuations. While such influence on the emitted radio photons significantly complicates their analysis, interpretation, and ability to extract the true physical properties from the observations, it also makes radio emissions a powerful and unique diagnostic of the heliospheric environment. This talk will showcase some of the fascinating diagnostic capabilities of solar radio bursts that make them beneficial to various heliosphysics disciplines. Such bursts have historically been used to obtain information on the exciters of the associated electrons and the acceleration mechanisms. However, recent studies demonstrated that solar radio bursts can also be used to diagnose the level and anisotropy of heliospheric density fluctuations, trace the configuration of the magnetic field, and even reveal the presence of magnetic switchbacks. They also constitute an asset in forecasting solar energetic particles (SEPs) and are thus an integral part of several space weather models.