Open AccessEvidence for electrostatic decay in the solar wind at 5.2 AU
Author(s) -
Thejappa G.,
MacDowall R. J.,
Scime E. E.,
Littleton J. E.
Publication year - 2003
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2002ja009290
Subject(s) - physics , solar wind , spacecraft , wavelength , ion acoustic wave , electric field , computational physics , plasma oscillation , acoustic wave , plasma , longitudinal wave , geophysics , atomic physics , wave propagation , optics , astronomy , quantum mechanics
The Unified Radio and Plasma wave Experiment (URAP) on the Ulysses spacecraft provides in situ observations of Langmuir waves and ion‐acoustic waves in the solar wind. The observations presented in this paper were obtained at 5.2 AU from the Sun. Low‐frequency (20–200 Hz in the spacecraft frame) electric field signals are observed coincident in time with the most intense Langmuir waves. The low‐frequency wave signals are identified as long‐wavelength ion‐acoustic waves. These observations provide evidence for the decay of Langmuir waves into daughter Langmuir and ion‐acoustic waves (the electrostatic decay process) in the solar wind.