Coalescence of Magnetic Flux Ropes in the Jovian Magnetodisk

Magnetic flux ropes (MFRs), as a kind of reconnection product, can further interact and merge into larger ones, leading to significant energy dissipation. While such a process has been extensively studied on Earth, it has never been reported in Jupiter’s magnetosphere. Here, by utilizing the Jupiter Near-polar Orbiter (Juno) measurements, we for the first time report a potential MFR coalescence event in Jupiter’s magnetodisk. Multiple adjacent MFRs are identified by their bipolar magnetic field signatures. In the interaction region between adjacent flux ropes, we observe intensified current density, enhanced electron heating, and significant electron energization over a broad energy range. These features are consistent with theoretical and observational signatures of flux rope coalescence. These results extend the concept of flux rope coalescence from terrestrial to giant planetary magnetospheres and have broader implications for energy dissipation processes in Jupiter’s magnetodisk.