ANISOTROPY IN FAST AND SLOW SOLAR WIND FLUCTUATIONS

摘要

Using 5 years of spacecraft data from near Earth orbit, we investigate the correlation anisotropy of solar wind magnetohydrodynamic-scale fluctuations and show that the nature of the anisotropy differs in fast ( > 500 km s~(-1)) and slow ( < 400 km s~(-1)) streams. In particular, fast streams are relatively more dominated by fluctuations with wavevectors quasi-parallel to the local magnetic field, while slow streams, which appear to be more fully evolved turbulence, are more dominated by quasi-perpendicular fluctuation wavevectors.