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Excitation of short‐scale density structures by drift waves during ionospheric heating
Author(s) -
Antani S. N.,
Guzdar P. N.
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl003603
Subject(s) - physics , dissipative system , striation , instability , ionosphere , plasma , dispersion relation , scaling , excited state , excitation , computational physics , dispersion (optics) , mixing (physics) , geophysics , atomic physics , mechanics , geology , condensed matter physics , optics , thermodynamics , quantum mechanics , geometry , paleontology , mathematics
In this paper we investigate the role of dissipative drift instability in exciting “needle‐like” short scale density structures recently observed during ionospheric heating [ Kelley et al., , 1995; Franz et al. , 1999]. A two‐fluid model for a warm, collisional plasma column, representing a typical density striation is used to derive a dispersion relation for drift modes. It is found that unstable drift modes can be excited. More accurate nonlocal eigenmode analysis reveals that for Arecibo parameters, the m = 3 mode is most unstable. Mixing‐length estimate of the density spectrum indicates a k −2 scaling in reasonable agreement with the observed spectrum.