Structured Energy Conversion in Kelvin‐Helmholtz Instability

We present quantitative investigations of the energy conversion pathways—electromagnetic , fluid flow , and particle thermal energies—within the Kelvin‐Helmholtz instability (KHI) observed by the Magnetospheric Multiscale mission. We find that KHI mediates and facilitates bidirectional energy conversions among three types of energy by analyzing Joule and pressure‐strain energy conversions. On both the magnetosphere (MSP) and magnetosheath (MSH) sides, is converted into , primarily driven by ion expansion. This suggests that the KHI acts as a relaxation mechanism, converting stored of compressed plasma at the magnetopause (MP) into associated with the KHI flow. Furthermore, the conversion between and is highly dependent on the spatial phase within the KHI structure: the MSP side converts to , while the MSH side converts to . This finding demonstrates that energy conversions are highly structured within the KHI.