Radar studies of midlatitude ionospheric plasma drifts

Scherliess, L.; Fejer, Bela G.; Holt, J.; Гончаренко, Л. П.; Amory‐Mazaudier, Christine; Buonsanto, M. J.

doi:10.1029/2000ja000229

Cited by 26 publications

(33 citation statements)

References 27 publications

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“…Both types of disturbances result mostly from the prompt penetration of magnetospheric electric fields from high to low latitudes. Both short-lived disturbances and longer-lasting disturbances in the zonal electric field were extensively studied through observations and models (Kelley et al, 1979;Spiro et al, 1981;Wand, 1981; Scherliess, 1998;Scherliess et al, 2001). Experimental data show that storm-time penetration electric fields can significantly depart from the average climatological pattern, and the sources of the large variability are not well understood (Fejer, 2002).…”

Section: Plasma Drifts and Their Effectsmentioning

confidence: 99%

Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars

et al. 2005

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Abstract. This paper describes the ionospheric response to a geomagnetic storm beginning on 17 April 2002. We present the measurements of ionospheric parameters in the F-region obtained by the network of eight incoherent scatter radars. The main effects of this storm include a deep decrease in the electron density observed at high and middle latitudes in the pre-noon sector, and a minor enhancement in the density observed in the daytime sector at middle latitudes. Extreme plasma heating (>1000−3000 K) is observed at high latitudes, subsiding to 200-300 K at subauroral latitudes. The western hemisphere radar chain observed the prompt penetration of the electric field from auroral to equatorial latitudes, as well as the daytime enhancement of plasma drift parallel to the magnetic field line, which is related to the enhancement in the equatorward winds. We suggest that in the first several hours after the storm onset, a negative phase above Millstone Hill (pre-noon sector) results from counteracting processes -penetration electric field, meridional wind, and electrodynamic heating, with electrodynamic heating being the dominant mechanism. At the lower latitude in the prenoon sector (Arecibo and Jicamarca), the penetration electric field becomes more important, leading to a negative storm phase over Arecibo. In contrast, in the afternoon sector at mid-latitudes (Kharkov, Irkutsk), effects of penetration electric field and meridional wind do not counteract, but add up, leading to a small (∼15%), positive storm phase over these locations. As the storm develops, Millstone Hill and Irkutsk mid-latitude radars observe further depletion of electron density due to the changes in the neutral composition.

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Section: Plasma Drifts and Their Effectsmentioning

confidence: 99%

Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars

et al. 2005

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“…Overall, the drifts at Bundoora have far more in common with ISR results for Millstone Hill (71.5 • W, 42.6 • N, geo- (Blanc and Amayenc, 1979;Blanc, 1983;Buonsanto and Witasse, 1999;Scherliess et al, 2000). However, there is some agreement between the meridional drifts measured at Bundoora and Saint Santin.…”

Section: Further Discussionmentioning

confidence: 60%

“…The velocities are assumed to correspond to true F-region ion drifts driven by ionospheric electric fields for the purpose of this analysis, and are compared with other empirical representations of mid-latitude electric fields (e.g. Buonsanto and Witasse, 1999;Scherliess et al, 2000). Despite limitations in our measurements (as with other techniques), the comparisons are promising.…”

Section: Introductionmentioning

confidence: 79%

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Seasonal and magnetic activity variations of ionospheric electric fields above the southern mid-latitude station, Bundoora, Australia

et al. 2001

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Abstract. We investigate the seasonal, local solar time, and geomagnetic activity variations of the average Doppler velocity measured by an HF digital ionosonde deployed at Bundoora, Australia (145.1 • E, 37.7 • S, geographic; 49 • S magnetic). The Doppler velocities were heavily averaged to suppress the short-term effects (<3 hours) of atmospheric gravity waves, and thereby obtain the diurnal variations attributed to the tidally-driven ionospheric dynamo and electric fields generated by magnetic disturbances. The observed seasonal variations in Doppler velocity were probably controlled by variations in the lower thermospheric winds and ionospheric conductivity above Bundoora and in the magnetically conjugate location. The diurnal variations of the meridional (fieldperpendicular) drifts and their perturbations exhibited a complex structure, and were generally smaller than the variations in the zonal drifts. The latter were basically strongly westward during the evening to early morning, and weakly eastward during the late morning to just past noon. The zonal perturbations were strongly enhanced by increasing geomagnetic activity, and closely resembled the perturbation drifts measured by the incoherent scatter radar (ISR) at Millstone Hill (71.5 • W, 42.6 • N; 57 • N). There was also some resemblance between the diurnal variations in the meridional drifts. Overall, the comparisons suggest that with sufficient averaging, Doppler velocities measured with digital ionosondes at mid-latitudes correspond to true ion motions driven by ionospheric electric fields. This is a useful result because apart from the ISRs located in the American-European sector, there are no ground-based instruments capable of measuring electric fields in the mid-latitude ionosphere.

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“…Behnke and Harper, 1973;Fejer, 1993), 40 • N magnetic) (e.g. Blanc, 1983;Buonsanto and Witasse, 1999;Scherliess et al, 2001);and Millstone Hill (43 • N geographic, 57 • N magnetic) (e.g. Evans, 1972;Buonsanto et al, 1993;Foster and Vo, 2002).…”

Section: Introductionmentioning

confidence: 99%

Solar and geomagnetic activity effects on mid-latitude F-region electric fields

et al. 2008

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Abstract. Diurnal patterns of average F-region ionospheric drift (electric field) and their dependence on solar and geomagnetic activity have been defined using digital ionosonde Doppler measurements recorded at a southern mid-latitude station (Bundoora 145.1 • E, 37.7 • S geographic, 49 • S magnetic). A unique database consisting of 300 907 drift velocities was compiled, mostly using one specific mode of operation throughout 1632 days of a 5-year interval (1999)(2000)(2001)(2002)(2003). The velocity magnitudes were generally larger during the night than day, except during the winter months (JuneAugust), when daytime velocities were enhanced. Of all years, the largest drifts tended to occur during the high speed solar wind streams of 2003. Diurnal patterns in the average quiet time (AE<75 nT) meridional drifts (zonal electric field) peaked at up to ∼6 m s −1 poleward (0.3 mV m −1 eastward) at 03:30 LST, reversing in direction at ∼08:30 LST, and gradually reaching ∼10 m s −1 equatorward at ∼13:30 LST. The quiet time zonal drifts (meridional electric fields) displayed a clear diurnal pattern with peak eastward flows of ∼10 m s −1 (0.52 mV m −1 equatorward) at 09:30 LST and peak westward flows around midnight of ∼18 m s −1 (0.95 mV m −1 poleward). As the AE index increased, the westward drifts increased in amplitude and they extended over a greater fraction of the day. The perturbation drifts changed in a similar way with decreasing D st except the daytime equatorward flows strengthened with increasing AE index, whereas they became weak for D st <−60 nT. The responses in all velocity components to changing solar flux values were small, but net poleward perturbations during the day were associated with large solar flux values (>192×10 −22 W m −2 Hz −1 ). These results help to more fully quantify the response of the midlatitude ionosphere to changing solar and geomagnetic conditions, as required to refine empirical and theoretical models of mid-latitude electric fields.Correspondence to:

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Radar studies of midlatitude ionospheric plasma drifts

Cited by 26 publications

References 27 publications

Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars

Observations of the April 2002 geomagnetic storm by the global network of incoherent scatter radars

Seasonal and magnetic activity variations of ionospheric electric fields above the southern mid-latitude station, Bundoora, Australia

Solar and geomagnetic activity effects on mid-latitude F-region electric fields

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