Unified View of Nonlinear Wave Structures Associated with Whistler-Mode Chorus

Abstract

A range of nonlinear wave structures, including Langmuir waves, unipolar electric fields, and bipolar electric fields, are often observed in association with whistler-mode chorus waves in near-Earth space. We demonstrate that the three seemingly different nonlinear wave structures originate from the same nonlinear electron trapping process by whistler-mode chorus waves. The ratio of the Landau resonant velocity to the electron thermal velocity controls the type of nonlinear wave structures that will be generated.