Speaker
Description
Solar radio bursts, produced by electrons travelling along magnetic field lines from the Sun through the heliosphere, are a unique diagnostic of the solar atmosphere. Remote radio observations from spacecraft, including Parker Solar Probe and Solar Orbiter, now offer a multi-vantage point view of radio bursts at different longitudes around the Sun. By analysing variations in the received peak flux density at each spacecraft, we show that the magnetic field not only guides the emitting electrons but also directs radio waves through scattering on anisotropic density fluctuations in the surrounding plasma that are aligned to the local field direction. Simulations of radio-wave propagation further demonstrate that the interplanetary magnetic field structure is encoded in the observed radio emission directivity, with large-scale channelling persisting over vast distances on the scale of half an au, even with relatively weak anisotropy. This channelling shifts the apparent position of radio sources by ~30 degrees at 200 kHz, complicating the association of these sources with a given active region without disentangling the scattering effects. Our analysis suggests that radio observations can be used to reconstruct magnetic field structures within turbulent media, offering a new method for diagnosing the large-scale field structure in the heliosphere.
