Statistical Analysis of the Electron Density Gradients in the Polar Cap F Region Using the Resolute Bay Incoherent Scatter Radar North

2018 ◽  
Vol 123 (5) ◽  
pp. 4066-4079 ◽  
Author(s):  
Victoriya V. Forsythe ◽  
Roman A. Makarevich
Keyword(s):  
Statistical Analysis ◽  
Electron Density ◽  
Density Gradients ◽  
Polar Cap ◽  
Incoherent Scatter Radar ◽  
Incoherent Scatter ◽  
F Region ◽  
Scatter Radar ◽  
Resolute Bay

scholarly journals Ground-based observations of the auroral zone and polar cap ionospheric responses to dayside transient reconnection

2002 ◽  
Vol 20 (6) ◽  
pp. 781-794 ◽  
Author(s):  
J. A. Davies ◽  
T. K. Yeoman ◽  
I. J. Rae ◽  
S. E. Milan ◽  
M. Lester ◽  
...  
Keyword(s):  
Electron Density ◽  
Plasma Density ◽  
Closed Field ◽  
Polar Cap ◽  
Incoherent Scatter Radar ◽  
Plasma Parameters ◽  
Flux Transfer Events ◽  
Incoherent Scatter ◽  
Scatter Radar ◽  
Flux Transfer

Abstract. Observations from the EISCAT VHF incoherent scatter radar system in northern Norway, during a run of the common programme CP-4, reveal a series of poleward-propagating F-region electron density enhancements in the pre-noon sector on 23 November 1999. These plasma density features, which are observed under conditions of a strongly southward interplanetary magnetic field, exhibit a recurrence rate of under 10 min and appear to emanate from the vicinity of the open/closed field-line boundary from where they travel into the polar cap; this is suggestive of their being an ionospheric response to transient reconnection at the day-side magnetopause (flux transfer events). Simultaneous with the density structures detected by the VHF radar, poleward-moving radar auroral forms (PMRAFs) are observed by the Finland HF coherent scatter radar. It is thought that PM-RAFs, which are commonly observed near local noon by HF radars, are also related to flux transfer events, although the specific mechanism for the generation of the field-aligned irregularities within such features is not well understood. The HF observations suggest, that for much of their existence, the PMRAFs trace fossil signatures of transient reconnection rather than revealing the footprint of active reconnection itself; this is evidenced not least by the fact that the PMRAFs become narrower in spectral width as they evolve away from the region of more classical, broad cusp scatter in which they originate. Interpretation of the HF observations with reference to the plasma parameters diagnosed by the incoherent scatter radar suggests that as the PMRAFs migrate away from the reconnection site and across the polar cap, entrained in the ambient antisunward flow, the irregularities therein are generated by the presence of gradients in the electron density, with these gradients having been formed through structuring of the ionosphere in the cusp region in response to transient reconnection.Key words. Magnetospheric physics (magnetosphere-ionosphere interaction) – ionosphere (ionospheric irregularities; plasma density and temperature)

scholarly journals Variations of topside ionospheric scale heights over Millstone Hill during the 30-day incoherent scatter radar experiment

2007 ◽  
Vol 25 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
L. Liu ◽  
W. Wan ◽  
M.-L. Zhang ◽  
B. Ning ◽  
S.-R. Zhang ◽  
...  
Keyword(s):  
Electron Density ◽  
Thermal Structure ◽  
Plasma Temperature ◽  
Scale Height ◽  
Incoherent Scatter Radar ◽  
Density Profiles ◽  
Incoherent Scatter ◽  
Scatter Radar ◽  
Vertical Scale ◽  
Electron Density Profiles

Abstract. A 30-day incoherent scatter radar (ISR) experiment was conducted at Millstone Hill (288.5° E, 42.6° N) from 4 October to 4 November 2002. The altitude profiles of electron density Ne, ion and electron temperature (Ti and Te), and line-of-sight velocity during this experiment were processed to deduce the topside plasma scale height Hp, vertical scale height VSH, Chapman scale height Hm, ion velocity, and the relative altitude gradient of plasma temperature (dTp/dh)/Tp, as well as the F2 layer electron density (NmF2) and height (hmF2). These data are analyzed to explore the variations of the ionosphere over Millstone Hill under geomagnetically quiet and disturbed conditions. Results show that ionospheric parameters generally follow their median behavior under geomagnetically quiet conditions, while the main feature of the scale heights, as well as other parameters, deviated significantly from their median behaviors under disturbed conditions. The enhanced variability of ionospheric scale heights during the storm-times suggests that the geomagnetic activity has a major impact on the behavior of ionospheric scale heights, as well as the shape of the topside electron density profiles. Over Millstone Hill, the diurnal behaviors of the median VSH and Hm are very similar to each other and are not so tightly correlated with that of the plasma scale height Hp or the plasma temperature. The present study confirms the sensitivity of the ionospheric scale heights over Millstone Hill to thermal structure and dynamics. The values of VSH/Hp tend to decrease as (dTp/dh)/Tp becomes larger or the dynamic processes become enhanced.

scholarly journals Validation of Clyde River SuperDARN radar velocity measurements with the RISR-C incoherent scatter radar

2018 ◽  
Vol 36 (6) ◽  
pp. 1657-1666 ◽  
Author(s):  
Alexander Koustov ◽  
Robert Gillies ◽  
Peter Bankole
Keyword(s):  
High Frequency ◽  
Hf Radar ◽  
Plasma Velocity ◽  
Velocity Measurements ◽  
Incoherent Scatter Radar ◽  
Incoherent Scatter ◽  
Radar Network ◽  
Scatter Radar ◽  
Radar Velocity ◽  
Resolute Bay

Abstract. The study considers simultaneous plasma velocity measurements in the eastward direction carried out by the Clyde River (CLY) Super Dual Auroral Radar Network (SuperDARN) high-frequency (HF) radar and Resolute Bay (RB) incoherent scatter radar – Canada (RISR-C). The HF velocities are found to be in reasonable agreement with RISR velocities up to magnitudes of 700–800 m s−1 while, for faster flows, the HF velocity magnitudes are noticeably smaller. The eastward plasma flow component inferred from SuperDARN convection maps (constructed for the area of joint measurements with consideration of velocity data from all the radars of the network) shows the effect of smaller HF velocities more notably. We show that the differences in eastward velocities between the two instruments can be significant and prolonged for observations of strongly sheared plasma flows.

Variations of electron density based on long-term incoherent scatter radar and ionosonde measurements over Millstone Hill

Radio Science ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jiuhou Lei ◽  
Libo Liu ◽  
Weixing Wan ◽  
Shun-Rong Zhang
Keyword(s):  
Electron Density ◽  
Incoherent Scatter Radar ◽  
Incoherent Scatter ◽  
Scatter Radar
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