title: Eigenmode structure in solar-wind Langmuir waves.
abstract: We show that observed spatial- and frequency-domain signatures of intense solar-wind Langmuir waves can be described as eigenmodes trapped in a parabolic density well. Measured solar-wind electric field spectra and waveforms are compared with 1D linear solutions and, in many cases, can be represented by 1-3 low-order eigenstates. To our knowledge, this report is the first observational confirmation of Langmuir eigenmodes in space. These results suggest that linear eigenmodes may be the starting point of the nonlinear evolution, critical for producing solar type II and type III radio bursts.
authors.affiliation: Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Ergun
authors.forename: D M
authors.initials: DM
authors.lastname: Malaspina
authors.forename: Iver H
authors.initials: IH
authors.lastname: Cairns
authors.forename: M V
authors.initials: MV
authors.lastname: Goldman
authors.forename: D L
authors.initials: DL
authors.lastname: Newman
authors.forename: P A
authors.initials: PA
authors.lastname: Robinson
authors.forename: S
authors.initials: S
authors.lastname: Eriksson
authors.forename: J L
authors.initials: JL
authors.lastname: Bougeret
authors.forename: C
authors.initials: C
authors.lastname: Briand
authors.forename: S D
authors.initials: SD
authors.lastname: Bale
authors.forename: C A
authors.initials: CA
authors.lastname: Cattell
authors.forename: P J
authors.initials: PJ
authors.lastname: Kellogg
authors.forename: M L
authors.initials: ML
authors.lastname: Kaiser