Numerous Nanoflare-Like Interchange Reconnection Events Inject Energetic Particles into the Solar Wind

How the solar wind is heated to over a million degrees and accelerated to supersonic speeds remains an unresolved problem. One promising mechanism invokes numerous nanoflare-like energy release events driven by interchange reconnection between open and closed magnetic field lines in the solar corona, yet direct evidence for their ubiquity and particle-acceleration nature has been elusive. Using ultra-sensitive radio imaging spectroscopy, we detect extremely frequent and faint type III radio bursts originating from regions near open–closed magnetic boundaries in the low solar corona. These bursts trace energetic electrons produced by prevalent interchange reconnection events, injecting energy, momentum, and particles into the solar wind. Direct in situ measurements from the Parker Solar Probe reveal suprathermal electrons and ions in the near-Sun solar wind consistent with particle injections from these regions. Together, these observations uncover a previously inaccessible spectrum of particle-accelerating, small-scale interchange reconnection events and provide new insight into the long-standing problem of coronal heating and solar wind acceleration.