CME-HSS Interaction and Characteristics Tracked from Sun to Earth.

In a thorough study, we investigate the origin of a remarkable plasma and magnetic field configuration observed on June 22, 2011, near L1, which appears to be a magnetic ejecta (ME) and a shock signature engulfed by a solar wind high-speed stream (HSS). We identify the signatures as an Earth-directed coronal mass ejection (CME), associated with a C7.7 flare on June 21, 2011, and its interaction with a HSS, which emanates from a coronal hole (CH) close to the launch site of the CME. The results indicate that the major interaction between the CME and the HSS starts at a height of up to . Over that distance range, the CME undergoes a strong north-eastward deflection of at least due to the open magnetic field configuration of the CH. We perform a comprehensive analysis for the CME-HSS event using multi-viewpoint data (from the , the and the ), and combined modeling efforts (nonlinear force-free field modeling, CME modeling, and the model). We aim at better understanding its early evolution and interaction process as well as its interplanetary propagation and related signatures, and finally the resulting impact on the Earth's magnetosphere.