Articles | Volume 33, issue 8
Regular paper
14 Aug 2015
Regular paper |  | 14 Aug 2015

Nonlinear wave interactions of kinetic sound waves

G. Brodin and L. Stenflo

Abstract. We reconsider the nonlinear resonant interaction between three electrostatic waves in a magnetized plasma. The general coupling coefficients derived from kinetic theory are reduced here to the low-frequency limit. The main contribution to the coupling coefficient we find in this way agrees with the coefficient recently presented in Annales Geophysicae. But we also deduce another contribution which sometimes can be important, and which qualitatively agrees with that of an even more recent paper. We have thus demonstrated how results derived from fluid theory can be improved and generalized by means of kinetic theory. Possible extensions of our results are outlined.

Short summary
We reconsider the interaction of waves in a magnetized plasma, with a focus on the solar wind. The importance of a kinetic description, taking the detailed velocity distribution of electrons and ions into account, is emphasized. Our result for the coupling strength between different wave modes agrees with previous results in the limiting case when kinetic effects are negligible, however.