Event Study of Dayside ULF waves using Ground- and Space-based Magnetometer Measurements

We investigate an event study of large-scale dayside ULF waves seen in magnetometer measurements from different altitudes. ULF waves are seen from multiple ground-based magnetometers in the Magnetometer Array for Cusp and Cleft Studies (MACCS) chain located in East Canada on 2024/03/09 for a long period of time on the dayside. Swarm satellite A and C fly overhead three of the ground magnetometers during the ULF wave activities while GOES-16 flies in the equatorial plane at a close longitude for the same time period. Magnetic field measurements from the ground- and two space-based magnetometers are analyzed using wavelet analysis to find if consistent ULF wave signals can be seen from all three measurements at different altitudes.
We find the ULF wave signals to be consistent and similar for the ground magnetometers and GOES satellite due to its relatively stable location traced back onto the ground. The Swarm satellites fly over the high-latitude region from 60˚ to 80˚in ~3 minutes and fly through turbulent plasma, making it challenging to associate the Swarm measurements to lower frequency signals at the Pc5 ranges observed on the ground and from the magnetosphere. However, higher frequency ULF waves at ~15 mHz, consistent with other measurements, can be detected from the Swarm measurements.