STATISTICAL METHODS FOR MULTI-SCALE ANALYSIS OF INTERPLANETARY MAGNETIC FIELD FLUCTUATIONS

An ICME event can be observed between DOY 23.958 - DOY 24.854, 2001, its signatures being analyzed in this paper considering the data from Ulysses/VHM and SWOOPS instruments. The presence of a magnetic cloud in the interval DOY 23.958 - DOY 24.665 is also analyzed by means of the minimum variance analysis (MVA). The technique based on differencing of the original time series over a range of temporal scales is applied for the study of statistical properties of the interplanetary magnetic field fluctuations along a period of three days, starting on DOY 23, 2001. The intermittency, that is connected with sudden occurrence of large amplitude variations of magnetic field intensity, is usually pointed out as a departure of the probability distribution functions (PDFs) from a Gaussian distribution. For the studied period of time, the fluctuations of the magnetic field magnitude (B), and the corresponding RTN components (Br, Bt, Bn) at larger scales are less intermittent than at small scales. Also, their behavior at different scales is quantitatively described by the PDFs and generalized structure functions.