Evaluation of bispectrum in the wave number domain based on multi-point measurements

Y. Narita (1) , K.H. Glassmeier (1) , Pierrette Décréau (2) , T. Hada (3) , U. Motschmann (4) , Y. Nariyuki (5)

1 IGEP - Institut für Geophysik und Extraterrestrische Physik [Braunschweig]
2 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
3 Kyushu University
4 Institut für Theoretische Physik [Braunschweig]
5 ESST - Department of Earth System Science and Technology [Fukuoka]

We present an estimator of the bispectrum, a measure of three-wave couplings. It is evaluated directly in the wave number domain using a limited number of detectors. The ability of the bispectrum estimator is examined numerically and then it is applied to fluctuations of magnetic field and electron density in the terrestrial foreshock region observed by the four Cluster spacecraft, which indicates the presence of a three-wave coupling in space plasma.

Keywords: Interplanetary physics; Plasma waves and turbulence; Space plasma physics; Experimental and mathematical techniques; Wave-wave interactions

Domains: Space Physics [physics.space-ph]

Y. Narita, K.H. Glassmeier, Pierrette Décréau, T. Hada, U. Motschmann, et al.. Evaluation of bispectrum in the wave number domain based on multi-point measurements. Annales Geophysicae, 2008, 26 (11), pp.3389-3393. ⟨10.5194/angeo-26-3389-2008⟩. ⟨insu-02872008⟩