F region east‐west drifts at Jicamarca

Fejer, Bela G.; Farley, D. T.; Gonzales, C. A.; Woodman, R. F.; Calderón, César

doi:10.1029/ja086ia01p00215

Cited by 112 publications

(60 citation statements)

References 24 publications

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“…The velocity reaches as large as 140 ms −1 around sunset and decreases with local time at the rate of approximately 10 ms −1 h −1 . Such time variation of zonal drift of the ESF plumes is consistent with the plasma drift velocity measured with the incoherent backscatter technique at Jicamarca, a velocity controlled by the downward dynamo electric field in the nighttime (Fejer et al, 1981). Assuming that equatorial plasma bubbles occur at apex sunset and that their eastward drift velocity is represented by the linear regression line in Fig.…”

Section: Backtrace Of Plasma Plumessupporting

confidence: 50%

Eastward traverse of equatorial plasma plumes observed with the Equatorial Atmosphere Radar in Indonesia

et al. 2006

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Abstract. The zonal structure of radar backscatter plumes associated with Equatorial Spread F (ESF), probably modulated by atmospheric gravity waves, has been investigated with the Equatorial Atmosphere Radar (EAR) in West Sumatra, Indonesia (0.20 • S, 100.32 • E; dip latitude 10.1 • S) and the FM-CW ionospheric sounders on the same magnetic meridian as the EAR. The occurrence locations and zonal distances of the ESF plumes were determined with multibeam observations with the EAR. The ESF plumes drifted eastward while keeping distances of several hundred to a thousand kilometers. Comparing the occurrence of the plumes and the F-layer uplift measured by the FM-CW sounders, plumes were initiated within the scanned area around sunset only, when the F-layer altitude rapidly increased. Therefore, the PreReversal Enhancement (PRE) is considered as having a zonal variation with the scales mentioned above, and this variation causes day-to-day variability, which has been studied for a long time. Modulation of the underlying E-region conductivity by gravity waves, which causes inhomogeneous sporadic-E layers, for example, is a likely mechanism to determine the scale of the PRE.

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Section: Backtrace Of Plasma Plumessupporting

confidence: 50%

Eastward traverse of equatorial plasma plumes observed with the Equatorial Atmosphere Radar in Indonesia

et al. 2006

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“…Since then, numerous studies of the dependence of the zonal plasma drift on neutral wind interactions, solar irradiance, and geomagnetic activity have been undertaken (e.g. Fejer et al, 1981Fejer et al, , 1985Fejer et al, , 1991Fejer, 1993;Fejer and Scherliess, 1998;Sobral and Abdu, 1991;Sobral et al, 1999;Scherliess and Fejer, 1998;Valladares et al, 1996;de Paula et al, 2002). The work described in this report is the first space-based imaging study that addresses the topics previously studied using only ground-based or in-situ measurements.…”

Section: Introductionmentioning

confidence: 89%

Global observations of the zonal drift speed of equatorial ionospheric plasma bubbles

et al. 2004

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Abstract. Space-based measurements from an imager aboard the high-apogee NASA-IMAGE satellite allows for global-scale observations of nightside ionospheric densities and structure. Such a view cannot be provided by imagers in near-Earth orbit or based on the ground. The IMAGE Spectroscopic Imager (SI) isolates the Far-ultraviolet (FUV) O I 135.6 nm emission which is produced through radiative recombination of O + . These observations clearly show the distribution of FUV emissions of the equatorial airglow bands over the range of local times between the evening terminator to points well after midnight. Determination of plasma drift speeds in these local time sectors is performed by identification and subsequent tracking of localized depressions in the FUV emissions. This determination is made for nearly 200 plasma bubbles in the March-May period of 2002. Important findings of this study include (1) an unambiguous association between D st and zonal plasma drift speeds, and (2) a longitudinal dependence of the zonal plasma drift speeds, with a peak around the Indian sector. The first effect is attributed to penetrating ring current electric fields, while the second is apparently due to a longitudinal variability in the vertical polarization electric fields that directly affects the zonal plasma drift speeds.

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“…A better method of comparing zonal drift speeds is to map them down to a standard height. Since velocities in the F-layer are well known (e.g., Mazaudier and Venkateswaran, 1990;Fejer et al, 1981;Kudeki et al, 1981), we map all drift velocities to 300 km. Given the equation of a dipole field line…”

Section: New Interpretation -Magnetic-field Shadowsmentioning

confidence: 99%

Improved analysis of plasmasphere motion using the VLA radio interferometer

Hoogeveen

Jacobson

1997

Ann Geophysicae

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Abstract.Observations using the very large array (VLA) radio interferometer during the past five years have enabled the discovery of a new type of plasmasphere disturbance, the magnetic eastward-directed wave. Previous work indicated these disturbances were likely frozen to the geomagnetic field as determined from their azimuth distributions. This work provides a method to explain more accurately the azimuth distribution, thereby allowing the calculation of the disturbances' location in the plasmasphere independently of the measured velocity. The measurable velocity due to corotation is calculated and subtracted from the measured trace velocity. This difference, or deviation from corotation, is attributed to electrodynamic convection; the measurement of plasmaspheric convection may lead to the eventual monitoring of mid-latitude electric fields. Disturbances are seen convecting predominantly westward, with the fastest having angular velocities greater than the anticorotating VLA line of sight. The direction of convection and conditions of observations indicate that the disturbances are likely the same phenomenon seen by the Los Alamos satellite beacon array.

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F region east‐west drifts at Jicamarca

Abstract: F region east-west drifts have observations with other related data (such as the been measured at Jicamarca for almost 10 years, Indian results) and with available theory. using incoherent scatter. The drifts are west-

Cited by 112 publications

References 24 publications

Eastward traverse of equatorial plasma plumes observed with the Equatorial Atmosphere Radar in Indonesia

Eastward traverse of equatorial plasma plumes observed with the Equatorial Atmosphere Radar in Indonesia

Global observations of the zonal drift speed of equatorial ionospheric plasma bubbles

Improved analysis of plasmasphere motion using the VLA radio interferometer

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