In the solar wind, particle motion is governed by electromagnetic fields over a wide range of spatial and temporal scales. While low-frequency fields have been intensely studied for more than half a century, their high-frequency counterpart has become accessible only recently, thanks to the development of high-frequency instruments that can directly measure the waveforms of electric and magnetic fields. Such instruments are now operating on the Parker Solar Probe and Solar Orbiter missions. They have revealed a wealth of waves and structures in the inner heliosphere, many of which had previously gone unnoticed because prior observations mainly came as spectral products.
Thanks to these new observations and to the distinct orbits of the heliospheric missions, we are now in a unique position to perform detailed studies and investigate their radial dependence between 0.05 and 1 AU. This in turn opens up the possibility of addressing long-standing questions about their evolution and general properties, such as the dispersion and nonlinear evolution of electromagnetic waves, the evolution of coherent and incoherent structures such as electron and ion holes, current sheets and solitary structures, and the emission and propagation of transverse electromagnetic (radio) waves.
This session aims to highlight the scientific potential of these fascinating high-frequency electric and magnetic data, with a particular focus on recent results from the Parker Solar Probe and Solar Orbiter missions. By bringing together theorists and observers, our goal is to better understand and provide new insights into the sources and radial evolution of these high-frequency emissions.