ON EXPERIMENTAL-EVIDENCE OF CHAOTIC DYNAMICS OVER SHORT-TIME SCALES IN SOLAR-WIND AND COMETARY DATA USING NONLINEAR PREDICTION TECHNIQUES

Strong indications of chaotic dynamics underlying in the interplanetar y and cometary magnetic field fluctuations over short time scales are identified using HEOS-2 spacecraft (at 1 AU), Pioneer 10 (at 4.8 AU), Pioneer 11 (at 20 AU) and ICE (Giacobini-Zinner cometary environment) high-resolution measurements. Other non-chaotic candidate processes, s uch as linear deterministic models, fractal Brownian motion, and linea r gaussian stochastic models are rejected at a high confidence level u sing nonlinear prediction methods. Experimental proofs of phase correl ations are obtained. Assuming chaotic dynamics, estimations of the Kol mogorov-Sinai entropy are provided.