Event Details

Ultra Low Frequency waves in planetary magnetospheres: their sources, structures, and implications

Ultra low frequency (ULF) waves are a ubiquitous feature of planetary magnetospheres. They are an important conduit for the transfer of energy and momentum throughout such astrophysical bodies. The occurrence, frequencies, structure and polarisation of such wave modes also have much to tell us about the sources of the waves, and the structure of the magnetospheres in which they propagate. Here I will review the modes expected for these plasma waves, and use these characteristics to show how they may be employed to remote sense the structures of the magnetospheres in which they form. This includes using the frequencies and harmonic structures of the waves to determine the distribution of cold plasma on the planetary magnetic field lines, and using their growth and decay to monitor the magnetospheric hot plasma populations, as they interact with the wave electric fields. Examples will be taken from the magnetospheres of Earth, Mercury, Jupiter and Saturn.