scholarly journals Incoherent Scatter radar study of the impact of the meteoric influx on nocturnal E-region ionization

1999 ◽  
Vol 26 (13) ◽  
pp. 1833-1836 ◽  
Author(s):  
Q. H. Zhou ◽  
J. D. Mathews ◽  
Q. N. Zhou
2013 ◽  
Vol 31 (7) ◽  
pp. 1163-1176 ◽  
Author(s):  
R. A. Makarevich ◽  
A. V. Koustov ◽  
M. J. Nicolls

Abstract. A comprehensive 2-year dataset collected with the Poker Flat Incoherent Scatter Radar (PFISR) located near Fairbanks, Alaska (MLAT = 65.4° N) is employed to identify and analyse 22 events of anomalous electron heating (AEH) in the auroral E region. The overall AEH occurrence probability is conservatively estimated to be 0.3% from nearly-continuous observations of the E region by PFISR, although it increases to 0.7–0.9% in the dawn and dusk sectors where all AEH events were observed. The AEH occurrence variation with MLT is broadly consistent with those of events with high convection velocity (>1000 m s−1) or electron temperature (> 800 K), except for much smaller AEH probability and absence of AEH events near magnetic midnight. This suggests that high convection electric field by itself is necessary but not sufficient for measurable electron heating by two-stream plasma waves. The multi-point observations are utilised to investigate the fundamental dependence of the electron temperature on the convection electric field, focusing on the previously-proposed saturation effects at extreme electric fields. The AEH dataset was found to exhibit considerable scatter and, on average, similar rate of the electron temperature increase with the electric field up to 100 mV m−1 as compared with previous studies. At higher (highest) electric fields, the electron temperatures are below the linear trend on average (within uncertainty). By employing a simple fluid model of AEH, it is demonstrated that some of this deviation from the linear trend may be due to a stronger vibrational cooling at very large temperatures and electric fields.


2015 ◽  
Vol 1 (3) ◽  
pp. 37-48
Author(s):  
Александр Щербаков ◽  
Aleksandr Shcherbakov ◽  
Андрей Медведев ◽  
Andrey Medvedev ◽  
Дмитрий Кушнарев ◽  
...  

The paper sequentially presents technique for determining velocity of meridional neutral winds from the Irkutsk Incoherent Scatter Radar (IISR) data. Due to IISR specific features effective at other IS radars, techniques for determining ionosphere parameters, in particular plasma drift velocities, resulted in considerable variance of defined parameters. To measure the plasma drift velocity taking into account such IISR features, we have developed a special technique based on phase analysis of autocorrelation function of incoherent scatter signal. The technique needs to be tested, and for this purpose, an experiment was carried out to measure velocities of low-orbit satellites. However, methods for meridional neutral wind calculations used by many authors [Evans, 1970] with the use of drift velocities obtained before, resulted in great disagreements with empirical HWM93 and HWM07 wind models. In addition, simultaneous measurements at two frequencies at IISR showed that it was difficult to explain such differences without taking into account the cross-field movements. Possible underestimation of the impact of movements generated by electric fields can result in serious error in determining wind velocities. The paper considers improvements for methods of calculating winds, and shows that the results obtained with it are in a better agreement with wind models.


2011 ◽  
Vol 38 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
Q. H. Zhou ◽  
Y. T. Morton ◽  
C. M. Huang ◽  
N. Aponte ◽  
M. Sulzer ◽  
...  

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