Project: The role of low frequency plasma waves in large scale dynamics of planetary magnetospheres

Ultra low frequency (ULF) plasma waves in the outer boundary regions of planetary magnetospheres, the magnetosheath and the cusp, constitute an important element of the dynamics of plasma in that region. The plasma instabilities (e.g. ion-cyclotron or mirror instability) generating the waves provide the means of thermalization of anisotropic particle distributions in the absence of particle collisions. The proposed project is dedicated to investigation of these waves using in-situ data from recent spacecraft missions. In the magnetosheath of the Earth, detailed studies will be performed using combined multi-spacecraft measurements by Cluster, Themis and Double Star satellites, extracting information on the global distribution and temporal evolution of this phenomenon, their large scale structure and their interaction with boundary layers. Furthermore, we will use data from NASA Cassini and Messenger missions to compare the properties of observed ULF magnetosheath waves at Earth, Saturn and Mercury, where the same instabilities develop under significantly different conditions.

Funded by: GA ČR. GAP209/12/2394

Duration: 2012–2016

Investigator: Souček, J.