Heliospheric current sheet distortions from adjacent outflowing transients: Multi-spacecraft observations

Abstract

The heliospheric current sheet (HCS) is a permanent solar wind feature, with well predicted Earth passages, but it can be structured and its main orientation can be highly distorted. We report new observations from 2 spacecraft in the solar wind (supported by observations from 3 spacecraft in the nightside magnetosheath), showing an evolution across the Sun‐Earth line of large field reversals adjacent to the HCS. Contrary to a previously reported multi‐spacecraft event, this case shows that the field inversion structure cannot be assumed to be well preserved and close to planar on the scale of the magnetospheric cross‐section. However, both cases indicate the presence of field reversals in an away sector that is connected to the southern solar magnetic hemisphere but lies unexpectedly above a toward sector. Following the interpretation of the reversals as transient outflowing loops, associated initial flow deviations can be envisaged to account for the HCS deformations.