The role of ion drift in the formation of ionisation troughs in the mid- and high-latitude ionosphere—a review

Rodger, A. S.; Moffett, R. J.; Quegan, S.

doi:10.1016/0021-9169(92)90082-v

Cited by 224 publications

(308 citation statements)

References 120 publications

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“…Therefore we choose data from radar experiments with 360 ø azimuth scans. A distinctive feature of the midlatitude ionosphere is the existence of a density minimum; this local density minimum is termed the midlatitude trough (for a review, see Rodger et al [1992]). In Figure 3 we also plotted the density distribution.…”

Section: Observationsmentioning

confidence: 99%

Westward plasma drift in the midlatitude ionospheric F region in the midnight‐dawn sector

Huang¹,

Foster²,

Holt³

2001

J. Geophys. Res.

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Section: Observationsmentioning

confidence: 99%

Westward plasma drift in the midlatitude ionospheric F region in the midnight‐dawn sector

Huang¹,

Foster²,

Holt³

2001

J. Geophys. Res.

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“…8. A simple calculation shows that increased chemical recombination rates, for an ion temperature of 2000 K and a velocity of 1.2 km s )1 (Rodger et al, 1992) can result in a depletion of this magnitude on such a time scale, though in practice the actual situation was undoubtedly more complex.…”

Section: Eiscat Mainland Radarmentioning

confidence: 99%

Multi-instrument study of footprints of magnetopause reconnection in the summer ionosphere

et al. 2000

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Abstract. Results are presented from a multi-instrument investigation of the signatures of equatorial reconnection in the summer, sunlit ionosphere. Well-established ion dispersion signatures measured during three DMSP satellite passes were used to identify footprints in ionospheric observations made by radio tomography, and both the EISCAT ESR and mainland radars. Under the prevalent conditions of southward IMF with the Bz component increasing in magnitude, the reconnection footprint was seen to move equatorward through the ESR ®eld-of-view. The most striking signature was in the electron temperatures of the F2 region measured by the EISCAT mainland radar that revealed signi®cantly enhanced temperatures with a steep equatorward edge, in general agreement with the leading edge of the ion dispersion. It is suggested that this sharp transition in the electron temperature may be an indicator of the boundary, mapping from the reconnection site, between closed geomagnetic ®eld lines and those opened along which magnetosheath ions precipitate.

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“…Thus it is likely that F region echoes were lost during the event because large holes and patches of ionization were being formed. Troughs and holes in the ionosphere are created by ion heating driven by surges in ion velocity associated with flux transfer events [Rodger et al, 1992]. Ion heating also leads to an upward flow of ions [Sellek et al, 1992].…”

Section: Signatures Of a Major Cusp Event February 16 1996mentioning

confidence: 99%

Signatures of the ionospheric cusp in digital ionosonde measurements of plasma drift above Casey, Antarctica

Parkinson¹,

Breed²,

Dyson³

et al. 1999

J. Geophys. Res.

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Abstract. Signatures of the ionospheric cusp in HF digital ionosonde measurements of plasma drift made at the polar cap station Casey, Antarctica (-80.8 ø geomagnetic latitude), are investigated. Measurements recorded during the campaign interval February 13-17, 1996, are considered in this case study because the summer dipole tilt effect, and an interplanetary magnetic field (IMF) northward condition on February 16, were favorable for the detection of the cusp at a higher than usual latitude. On February 14 and 15 the magnitude of the IMF was about 4-6 nT, and the station probably passed just poleward of the cusp. The most general signatures of the cusp were enhanced electric field and electric field turbulence shown by increased drift velocity and velocity scatter in the convection throat, respectively. Broadband, unstructured fluctuations in the geomagnetic field measured by magnetometers near to noon are well known to be a signature of cusp currents and were associated with the intervals of enhanced convection turbulence. A major cusp event occurred above Casey on February 16, when the magnitude of the IMF increased from about 5 to > 10 nT. Cusp signatures during this event included the drift velocity surging to large values just before and after an interval during which the F region echoes were lost because of an absence of F region ionization and the formation of electron density patches. The loss of echoes was only partly explained by increased absorption and scatter of the transmitted radio waves. Although the spectral width of Doppler peaks increased, this, by itself, was not a unique signature of the cusp because the obliquity of echoes also controlled the spectral width in our near-vertical interferometry. However, signatures of the cusp were easily recognized in digisonde data, and the cusp's location and dynamics can be monitored using digisondes.

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The role of ion drift in the formation of ionisation troughs in the mid- and high-latitude ionosphere—a review

Cited by 224 publications

References 120 publications

Westward plasma drift in the midlatitude ionospheric F region in the midnight‐dawn sector

Westward plasma drift in the midlatitude ionospheric F region in the midnight‐dawn sector

Multi-instrument study of footprints of magnetopause reconnection in the summer ionosphere

Signatures of the ionospheric cusp in digital ionosonde measurements of plasma drift above Casey, Antarctica

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