Statistics of the Interplanetary Magnetic Fields Observed at 0.72 AU and 1 AU

摘要： This paper presents the Interplanetary Magnetic Field (IMF) observations at 0.72 AU measured by Venus Express (VEX) and 1 AU by Advanced Composition Explorer (ACE) in 2007.The distributions of daily averages of B are lognormal in both locations.The multiscale structure of the magnetic field fluctuations was described by studying the increments of B over a range scales from 10 min to 21.3 hours.All the Probability Distribution Functions (PDFs) can be described quantitatively by Tsallis distribution function.On the ecliptic plane from 0.72 AU to 1 AU,the entropy index q increases with distance over all scales,indicating the intermittency of turbulence is growing.The widths of the PDFs at 0.72 AU are larger than those at 1 AU at all scales,which indicating the turbulence at 0.72 AU is more intense than that at 1 AU.This helps us understand the nature and development of the magnetic field fluctuations. （共6頁(yè)）