Statistical analysis of ground based magnetic field measurements with the field line resonance detector

Abstract

Abstract. In this paper we introduce the field line resonance detector (FLRD), a wave telescope technique which has been specially adapted to estimate the spectral energy density of field line resonance (FLR) phase structures in a superposed wave field. The field line resonance detector is able to detect and correctly characterize several superposed FLR structures of a wave field and therefore constitutes a new and powerful tool in ULF pulsation studies. In our work we derive the technique from the classical wave telescope beamformer and present a statistical analysis of one year of ground based magnetometer data from the Canadian magnetometer network CANOPUS, now known as CARISMA. The statistical analysis shows that the FLRD is capable of detecting and characterizing superposed or hidden FLR structures in most of the detected ULF pulsation events; the one year statistical database is therefore extraordinarily comprehensive. The results of this analysis confirm the results of previous FLR characterizations and furthermore allow a detailed generalized dispersion analysis of FLRs.

Ground‐based magnetometer determination of in situ Pc4–5 ULF electric field wave spectra as a function of solar wind speed

“…Note, however, that Baker et al [2003] did observe events around local noon, just a larger occurrence of FLRs at dawn and at dusk. Plaschke et al [2008] demonstrate that the most likely occurrence location on the ground for Pc5 FLRs is in the 65–70°CGM latitude range, i.e., locations corresponding to GILL‐FCHU used in this study. Furthermore, Plaschke et al [2008] showed clear evidence of significant occurrence of FLRs in the noon sector, detected with the wave telescope method.…”

Three-dimensional spatial structures of solar wind turbulence from 10 000-km to 100-km scales

“…The concept of the projection method for multi-point data analysis can further be applied to various fluctuation geometries, e.g. for spherical wave patterns (Constantinescu et al, 2006(Constantinescu et al, , 2007, and for phase-shifted wave patterns for field line resonances of geomagnetic fields (Plaschke et al, 2008).…”

Comment on “Formation of substorm Pi2: A coherent response to auroral streamers and currents” by Y. Nishimura et al.

“…Since the discovery that the evolution of the intensity of the optical auroral emissions during substorm onset is strongly tied to the growth of ULF wave amplitudes, tools have been developed in order to study the spectral properties of electromagnetic wave activity [e.g., Samson and Olson, 1980;Nosé et al, 1998;Milling et al, 2008;Plaschke et al, 2008;Murphy et al, 2009;Rae et al, 2009;Kataoka et al, 2009;Rae et al, 2012]. Such analysis tools would provide a significantly better approach to characterize any potential link between Pi2 waveforms and auroral emissions than the approach used in N12.…”