Hydromagnetic waves and instabilities associated with cometary ion pickup: ICE observations

摘要: The hydromagnetic turbulence surrounding comet Giacobini-Zinner is characterized by two dominent components: large amplitude, linearly polarized waves with periods near 10² s and circularly wave packets 3 s. latter appear in association variations field magnitude produced the long period waves. A third, commonly observed feature identified, consisting of a partial rotation magnetic (a hook-like structure) which also appears to be triggered possibility that are generated pickup freshly ionized cometary neutrals has been investigated. resonant instability identified Wu Davidson (1972) able account for terms ions water group. Application theory indicates growth rate proton cyclotron waves, as consequence hydrogen ion pickup, somewhat lower, due both higher neutral velocities longer ionization times. Several significant features hooks presently unexplained will require further study.