WAVELET BICOHERENCE ANALYSIS OF STRONG PLASMA TURBULENCE AT THE EARTHS QUASIPARALLEL BOW SHOCK

Nonlinear interactions in strong plasma turbulence have been investiga ted in the vicinity of the Earth's quasiparallel bow shock by making u se of magnetometer data from the AMPTE-UKS (Active Magnetospheric Part icle Tracer Explorers-United Kingdom Subsatellite) spacecraft. Using a new and more robust estimator of the bicoherence, it is shown that th e large-amplitude monolithic magnetic structures observed upstream the shock front interact with the whistler wave trains that accompany the m. A unified picture emerges, in which the whistlers progressively gro w from these soliton-like structures through nonlinear interaction, si milarly to the dynamical evolution of step-like profiles in the Kortew eg-de Vries equation. (C) 1995 American Institute of Physics.