Electron Acceleration Within Quasi‐Linear Magnetic Holes in Terrestrial Magnetosheath: A Statistical Analysis

Abstract Magnetic holes (MHs), prevalent in space and astrophysical plasmas, are key to particle acceleration; however, their mechanisms remain unclear. Using high‐resolution Magnetospheric Multiscale mission data, we quantify local electron Fermi, betatron, and E ∥ acceleration rates within 460 MHs in Earth's magnetosheath under the guiding center approximation. Our analysis shows that MH depth ( D MH ), spatial size ( L MH ), and background temperature anisotropy ( A MH ) critically influence acceleration rates. The total acceleration rate is inversely correlated with D MH but positively correlated with L MH and A MH . Fermi and betatron mechanisms predominantly accelerate electrons in the trailing part of the MH while decelerating them in the leading part, whereas E ∥ acceleration occurs throughout the MH. The magnitude of E || acceleration rates is generally greater than that of Fermi and betatron acceleration rates. These findings provide direct evidence of electron acceleration within MHs, enhancing our understanding of their role in plasma dynamics and energy transfer in space environments.