Premium
Short wavelength stabilization of the gradient drift instability due to velocity shear
Author(s) -
Huba J. D.,
Lee L. C.
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/gl010i004p00357
Subject(s) - instability , wavelength , physics , allowance (engineering) , drift velocity , shear (geology) , electric field , velocity gradient , electrojet , mechanics , magnetic field , optics , geology , earth's magnetic field , quantum mechanics , petrology , mechanical engineering , engineering
A nonlocal analysis of the gradient drift instability is presented. The new effect included in this theory is the allowance for an inhomogeneous electric field which produces a sheared drift velocity. It is found that velocity shear can stabilize the short wavelength modes of the instability, and preferentially excite a longer wavelength mode than would be expected based upon local theory. This result may explain the observations of dominant, long wavelength irregularities in the equatorial electrojet [Kudeki et al., 1982; Pfaff et al., 1982] and be relevant to the formation of auroral arc elements.