Multiscale Magnetic Reconnection in the Genesis of Young Slow Solar Wind

Abstract The genesis of solar wind remains elusive due to limited multi-instrument observations of its source regions. Here, we introduce a novel “see and touch” technique, integrating remote-sensing observations with in situ measurements from Parker Solar Probe (PSP). This approach allows us to obtain 3D trajectories of flow structures such as streamer blobs and explore their in situ properties. With this approach, we link blobs observed by remote sensing and high-density jets (HDJs) measured in situ. The blobs are embedded in streamer rays, while the HDJs are found when PSP crosses the heliospheric current sheet (HCS). Our findings suggest that large-scale blobs/HDJs originate from primary reconnection in the near-Sun HCS, while secondary reconnection in smaller-scale current sheets forms multiple flux ropes, which merge to trigger further small-scale reconnection. Detailed in situ analysis reveals that turbulent magnetic reconnection is a key mechanism for dissipating filamentary HCS and energizing plasmas in blobs/HDJs. The multiscale magnetic reconnection accelerates the proton core population and mixes it with the beam population, driving bulk acceleration and heating of the nascent slow solar wind.