Premium
Localized plasma depletion in the ionosphere and the equatorial spread F
Author(s) -
Basu B.,
Coppi B.
Publication year - 1983
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/gl010i009p00900
Subject(s) - ionosphere , instability , physics , rayleigh–taylor instability , plasma , geophysics , magnetic field , wavelength , dissipative system , electrical resistivity and conductivity , f region , geology , computational physics , mechanics , optics , quantum mechanics
A spatially localized gravity driven instability is proposed to be the likely candidate for the observed kilometer scale‐size density irregularities in the bottomside equatorial F region. It is noted that the classical Rayleigh‐Taylor instability, which relies on the frozen‐in condition (implying E · B =O) and is of the flute‐type ( k · B =O), is not compatible with the experimental observations of density perturbations that have a finite extent along the magnetic field lines, while dissipative localized modes, which allow the plasma to move through the magnetic field as a result of finite electrical resistivity effects are consistent with such experimental findings. These modes have three‐dimensional structures with wavelengths in the east‐west direction (λ ϕ ) of the order of a few kilometers.