THE SOLAR ORIGIN OF SMALL INTERPLANETARY TRANSIENTS

Abstract

In this paper, we present evidence for magnetic transients with small radial extents ranging from 0.025 to 0.118 AU measured in situ by the Solar-Terrestrial Relations Observatory (STEREO) and the near-Earth Advanced Composition Explorer (ACE) and Wind spacecraft. The transients considered in this study are much smaller (STEREO images. The associated in situ signature is not that of a magnetic field rotation but rather of a temporary reversal of the magnetic field direction. Due to its “open-field topology,” we speculate that this structure is partly formed near helmet streamers due to reconnection between closed and open magnetic field lines. The implications of these observations for our understanding of the variability of the slow solar wind are discussed.