Publications

We have analyzed a highly monochromatic (f = 1.67 mHz) and large-amplitude Ultra Low Frequency (ULF) wave event observed at satellites and ground observatories on 23 June 2020 during super solar quiet geomagnetic conditions. Using Deep Space Climate Observatory and THEMIS-B spacecraft, which were in the interplanetary medium, we have identified the possible driver of such global ULF wave activity in the impact of a small pressure pulse accompanied by a discontinuity in the magnetic field. During the same time interval, indirect evidence exists of a rapid reconfiguration of the magnetotail in the form of Pi2 waves in the night-side region. The analysis of energetic particle flux at ionospheric height (500 km) shows a direct connection between the ULF wave activity and particle precipitation.

We analyze a case event in which several fluctuations at discrete frequencies (f ≈ 1.3–1.5, 3.3–3.6, 4.4–4.6, and 5.9–6.2 mHz) were observed in the magnetosphere, after the impact of a sharp shock wave that, in the interplanetary medium, was followed by intense fluctuations in the solar wind parameters. The comparison between interplanetary, geosynchronous, and ground‐based observations revealed that following the Sudden Impulse, magnetospheric modes at the same discrete frequencies were detected at geostationary orbit by spacecraft located in the morning and the dawn sector, and, ubiquitously, at ground‐based stations: all of them revealed a one‐to‐one correspondence with those ultimately identified in the high‐velocity stream following the shock wave.