ELECTROSTATIC WAVE EXCITATION IN PLANETARY MAGNETOSPHERES - APPLICATION TO NEPTUNE

Voyager 2 observations of electrostatic electron and ion cyclotron har monic waves in Neptune's magnetosphere are addressed. A model of elect ron Bernstein modes generated by a loss cone distribution of superther mal electrons is scaled to Neptune parameters and a comparison of theo ry with the observed electron flux shows good agreement. A model of pr oton Bernstein modes generated by a ring distribution of Tritonogenic nitrogen ions is also investigated and satisfactory agreement with the data are obtained compatible with known properties of the magnetosphe re. The success of the model in accounting for electrostatic emissions observed by Voyager over a wide range of sampled parameters recommend s its general applicability to planetary magnetospheres.