In the ULFwave project, we will analyze and study ULF waves using magnetic and electric measurements from multiple ongoing space missions as well as ground-based instruments. Specifically, a comprehensive dataset will be completed for this purpose based on space-borne measurements collected at the equatorial plane ( THEMIS mission), at high magnetic latitudes ( Cluster mission) and low Earth orbit ( CHAMP mission). This will be complemented by measurements from ground-based observatories (SAMBA, CARISMA , THEMIS-ground , ENIGMA arrays and INTERMAGNET network).
Basic derived quantities of our analysis will include wavelet power spectra (E, B), wave peak frequency and amplitude, wave occurrence duration and timing with regard to major magnetospheric phenomena, like storms, substorms, radiation belt enhancements.
Since ULF waves influence strongly the Earth's magnetospheric dynamics, they are of particular relevance for space weather nowcasting and forecasting efforts. This project will focus on the central role that ULF waves in the dynamics of the outer radiation belt, through particle energization, scattering and transport across the magnetic field lines. The results of the waves' analysis and in particular, the characteristics of the ULF wave propagation will be used to advance the current understanding of the radiation belt wave environment. Such information is crucial for modeling wave-particle interactions.
In the preparation phase of Swarm, the analysis of specific ULF waves can help understand the processes that play a crucial role in generating the waves with specific propagation characteristics. The latter is expected to be coupled with radiation belts and ring currents. Present day data from CHAMP, Cluster and THEMIS can be used to study this topic in detail. A better understanding of the process and wave propagation will provide the opportunity for geophysical validation of some of the Swarm products, especially those related to the vector magnetic and electric field data.
The overall expected benefits from the study are:
- Improved understanding of the wave activity / propagation and the underlying processes.
- Analysis of existing satellite and ground data also in view of potential LEO satellite validation (test with CHAMP in preparation of Swarm).
- Special focus on the additional opportunities that Swarm brings through magnetic and electric field (and density) data from a constellation of satellites also in view of potential new products/user tools.
- Projection of the ideas for the Swarm lifetime especially the expected combination with Cluster at that time.