THEMIS Observations of Field Line Resonance Excitation in Responce to a Solar Wind Pressure Pulse

The THEMIS multi-probe mission performs electric and magnetic field measurements with identical instrumentation at different locations, providing unique opportunities to differentiate between temporal and spatial characteristics of Field Line Resonances (FLRs) and to identify their extent in the Earth magnetosphere. In the case study presented, narrow-band FLRs are observed to be excited globally at different frequencies that match the local field line resonant frequency; for one instance where the intensification of the FLR power coincides with a solar wind pressure pulse, we are able to conclusively and definitively identify the excitation mechanism, and we thus consider this instance to be a proof that FLRs can be excited globally at the local FLR frequency by a solar wind pressure pulse.