The fast solar wind that fills the heliosphere originates from deep within regions of open magnetic field on the Sun called ‘coronal holes’. The energy source responsible for accelerating the plasma is widely debated; however, there is evidence that it is ultimately magnetic in nature, with candidate mechanisms including wave heating^1,2 and interchange reconnection^3,4,5. The coronal magnetic field near the solar surface is structured on scales associated with ‘supergranulation’ convection cells, whereby descending flows create intense fields. The energy density in these ‘network’ magnetic field bundles is a candidate energy source for the wind. Here we report measurements of fast solar wind streams from the Parker Solar Probe (PSP) spacecraft⁶ that provide strong evidence for the interchange reconnection mechanism. We show that the supergranulation structure at the coronal base remains imprinted in the near-Sun solar wind, resulting in asymmetric patches of magnetic ‘switchbacks’^7,8 and bursty wind streams with power-law-like energetic ion spectra to beyond 100 keV. Computer simulations of interchange reconnection support key features of the observations, including the ion spectra. Important characteristics of interchange reconnection in the low corona are inferred from the data, including that the reconnection is collisionless and that the energy release rate is sufficient to power the fast wind. In this scenario, magnetic reconnection is continuous and the wind is driven by both the resulting plasma pressure and the radial Alfvénic flow bursts.

充满日球层的快速太阳风起源于太阳上称为“日冕洞”的开放磁场区域深处。负责加速等离子体的能源受到广泛争论。然而，有证据表明它本质上是磁性的，候选机制包括波加热^1,2和互换重联^3,4,5。太阳表面附近的日冕磁场是在与“超颗粒”对流单元相关的尺度上构造的，由此下降的气流产生强场。这些“网络”磁场束中的能量密度是风的候选能源。^{在这里，我们报告了来自帕克太阳探测器 (PSP) 航天器6}的快速太阳风流的测量结果为立交重连机制提供了有力的证据。我们表明，日冕底部的超颗粒结构在近太阳太阳风中留下了印记，导致磁“之字形折返” ^7,8的不对称斑块和具有超过 100 keV 的幂律类高能离子谱的突发风流。交换重新连接的计算机模拟支持观察的关键特征，包括离子光谱。从数据中推断出低电晕立交桥重联的重要特征，包括重联是无碰撞的，能量释放率足以为快风提供动力。在这种情况下，磁重联是连续的，风是由产生的等离子体压力和径向阿尔芬流爆发驱动的。