HR: 0800h
AN: SH51C-1233    [Abstracts]
TI: Correlation Analysis of Turbulent Magnetic Fields at 1AU
AU: * Luo, Q
EM: luo@lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721 United States
AU: Giacalone, J
EM: giacalon@lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721 United States
AU: Jokipii, J R
EM: jokipii@lpl.arizona.edu
AF: University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ 85721 United States
AB: In this work we compute the correlation function of the interplanetary magnetic field using ACE and WIND observations. With two spacecraft at varying distances, a direct measure of the coherence scale is possible. We find, generally, that coherence scales in the directions both transverse and parallel to the fluctuating interplanetary magnetic field (IMF) are of the order 2M km. This is similar to previous estimates based on single spacecraft observations and the frozen-in and quastistatic assumptions. However, our results differ from those of previous studies in one important respect: we find that the IMF correlation function has a larger scale length in the direction parallel to the mean magnetic field compared to that perpendicular to it. This differs from previous findings based on single-spacecraft observations. We have also considered the effect of differing solar-wind velocities on the measured IMF coherence function. This will be discussed. Moreover, because of the nature of random IMF fluctuations, statistical uncertainties in the measured coherence scales can be significant. We will discuss techniques for reducing these uncertanties.
DE: 2109 Discontinuities (7811)
DE: 2114 Energetic particles (7514)
DE: 2134 Interplanetary magnetic fields
DE: 2149 MHD waves and turbulence (2752, 6050, 7836)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005