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The generation of non aspect sensitive plasma density irregularities by field aligned drifts in the lower ionosphere

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journal contribution
posted on 24.10.2012, 09:05 by T. R. Robinson, K. Schlegel
A theory of the generation of plasma density irregularities with virtually no aspect sensitivity, in the lower ionosphere at high latitudes, by electron drifts aligned with the geomagnetic field, is presented. The theory is developed through fluid equations in which the destabilising mechanism involves positive feedback from electron collisional heating. When field aligned electron drift speeds exceed a few km s-1, this effect destabilises waves with wavelengths in excess of a few tens of metres in the lower E-region, where collisional effects are sufficiently large. Furthermore, the threshold conditions are almost independent of the wave propagation direction and the unstable waves propagate at speeds well below the ion acoustic speed. The role that this new instability may play in recent radar backscatter observations of short scale irregularities propagating in directions close to that of the geomagnetic field, in the lower E-region is also considered.

History

Citation

ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES, 2000, 18 (7), pp. 799-806

Published in

ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES

Publisher

European Geosciences Union (EGU), Copernicus Publications, Springer Verlag (Germany)

issn

0992-7689

eissn

1432-0576

Copyright date

2000

Available date

24/10/2012

Publisher version

http://www.ann-geophys.net/18/799/2000/angeo-18-799-2000.html

Language

English