Jupiter‘s North Pole has a powerful magnetic field combined with plasma that has unusually low electron densities. This combination, researchers found, gives rise to a new type of plasma wave.
Ions in a magnetic field typically move parallel to magnetic field lines in Langmuir waves and perpendicularly to the field lines in AlfvΓ©nΒ waves — with each wave carrying a distinctive frequency signature. But in Jupiter’s strong magnetosphere, low-density plasma does something quite different: it creates what the team is calling an AlfvΓ©n-Langmuir wave — a wave that transitions from AlfvΓ©n-like to Langmuir-like, depending on wave number and excitation from local beams of electrons.
Although this is the first time such plasma behavior has been observed, the team suggests that other strongly-magnetized giant planets — or even stars — could also form these waves near their poles. (Image credit: NASA / JPL-Caltech / SwR I/ MSSS/G. Eason; research credit: R. Lysak et al.; via APS)
