scholarly journals Oscillations of the equatorward boundary of the ion auroral oval - radar observations

2008 ◽  
Vol 113 (A8) ◽  
pp. n/a-n/a ◽  
Author(s):  
P. T. Jayachandran ◽  
N. Sato ◽  
Y. Ebihara ◽  
A. S. Yukimatu ◽  
A. Kadokura ◽  
...  
Keyword(s):  
Auroral Oval ◽  
Radar Observations ◽  
Equatorward Boundary

scholarly journals Correspondence between the ULF wave power spatial distribution and auroral oval boundaries

2016 ◽  
Vol 2 (2) ◽  
pp. 46-65 ◽  
Author(s):  
Ольга Козырева ◽  
Olga Kozyreva ◽  
Вячеслав Пилипенко ◽  
Vyacheslav Pilipenko ◽  
Марк Энгебретсон ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spectral Power ◽  
Recovery Phase ◽  
Temporal Variations ◽  
Auroral Oval ◽  
Wave Power ◽  
Observational Result ◽  
Equatorward Boundary ◽  
Image Satellite ◽  
Magnetospheric Field

The world-wide spatial distribution of the wave power in the Pc5 band during magnetic storms has been compared with auroral oval boundaries. The poleward and equatorward auroral oval boundaries are estimated using either the British Antarctic Survey database containing IMAGE satellite UV observations of the aurora or the OVATION model based on the DMSP particle data. The “epicenter” of the spectral power of broadband Pc5 fluctuations during the storm growth phase is mapped inside the auroral oval. During the storm recovery phase, the spectral power of narrowband Pc5 waves, both in the dawn and dusk sectors, is mapped inside the auroral oval or around its equatorward boundary. This observational result confirms previously reported effects: the spatial/temporal variations of the Pc5 wave power in the morning/pre-noon sector are closely related to the dynamics of the auroral electrojet and magnetospheric field-aligned currents. At the same time, narrowband Pc5 waves demonstrate typical resonant features in the amplitude-phase latitudinal structure. Thus, the location of the auroral oval or its equatorward boundary is the preferred latitude for magnetospheric field-line Alfven resonator excitation. This effect is not taken into account by modern theories of ULF Pc5 waves, but it could be significant for the development of more adequate models.

scholarly journals Dayside cosmic noise absorption at the equatorward boundary of auroral oval as observed from Maitri, Antarctica ( L  = 5; CGM 62.45°S, 55.45°E)

2016 ◽  
Vol 121 (4) ◽  
pp. 3198-3211 ◽  
Author(s):  
Jayanta K. Behera ◽  
Ashwini K. Sinha ◽  
Geeta Vichare ◽  
Olga Kozyreva ◽  
Rahul Rawat ◽  
...  
Keyword(s):  
Auroral Oval ◽  
Noise Absorption ◽  
Equatorward Boundary ◽  
Cosmic Noise

scholarly journals Swarm Satellite and EISCAT Radar Observations of a Plasma Flow Channel in the Auroral Oval Near Magnetic Midnight

2018 ◽  
Vol 123 (6) ◽  
pp. 5140-5158 ◽  
Author(s):  
A. T. Aikio ◽  
H. Vanhamäki ◽  
A. B. Workayehu ◽  
I. I. Virtanen ◽  
K. Kauristie ◽  
...  
Keyword(s):  
Plasma Flow ◽  
Auroral Oval ◽  
Flow Channel ◽  
Radar Observations ◽  
Eiscat Radar ◽  
Swarm Satellite

scholarly journals SuperDARN E-region backscatter boundary in the dusk-midnight sector – tracer of equatorward boundary of the auroral oval

2002 ◽  
Vol 20 (12) ◽  
pp. 1899-1904 ◽  
Author(s):  
P. T. Jayachandran ◽  
E. F. Donovan ◽  
J. W. MacDougall ◽  
D. R. Moorcroft ◽  
J.-P. St. Maurice ◽  
...  
Keyword(s):  
Energy Flux ◽  
Proton Energy ◽  
Auroral Oval ◽  
Ionospheric Irregularities ◽  
Auroral Ionosphere ◽  
Particle Precipitation ◽  
Equatorward Boundary ◽  
E Region ◽  
Proton Aurora

Abstract. We compare the locations of the equatorward boundaries of SuperDARN E-region backscatter and Hb  emissions, focusing on the dusk-midnight sector of the auroral oval where the proton aurora is statistically located equatorward of the discrete electron aurora. We show that, whenever both boundaries can be simultaneously identified, they are coincident. Our result complements earlier studies, which demonstrated the correspondence between the DMSP b2i boundary and both the equatorward boundary of the proton auroral oval (Donovan et al., 2002), and the equatorward boundary of SuperDARN E-region echoes (Jayachandran et al., 2002). Further, our result shows that, provided there is sufficient precipitating proton energy flux, the SuperDARN radars can be used to monitor the equatorward edge of the proton auroral oval.Key words. Ionosphere (auroral ionosphere; particle precipitation; ionospheric irregularities)

On the relationship of the plasmapause to the equatorward boundary of the auroral oval and to the inner edge of the plasma sheet

1982 ◽  
Vol 87 (A11) ◽  
pp. 9059 ◽  
Author(s):  
J. L. Horwitz ◽  
W. K. Cobb ◽  
C. R. Baugher ◽  
C. R. Chappell ◽  
L. A. Frank ◽  
...  
Keyword(s):  
Plasma Sheet ◽  
Auroral Oval ◽  
Equatorward Boundary ◽  
Relationship Of ◽  
The Relationship

Substorm related CNA near equatorward boundary of the auroral oval in relation to interplanetary conditions

2015 ◽  
Vol 56 (1) ◽  
pp. 28-37 ◽  
Author(s):  
Jayanta K. Behera ◽  
Ashwini K. Sinha ◽  
Anand K. Singh ◽  
Geeta Vichare ◽  
Ajay Dhar ◽  
...  
Keyword(s):  
Auroral Oval ◽  
Equatorward Boundary

Identifying the plasmapause location from global auroral image data

2021 ◽  
Author(s):  
Michaela Mooney ◽  
Colin Forsyth ◽  
Mike Marsh ◽  
Jonathan Rae
Keyword(s):  
Image Data ◽  
Auroral Oval ◽  
Inner Magnetosphere ◽  
Equatorward Boundary ◽  
Direct Measurements ◽  
Scale Models ◽  
Far Ultraviolet ◽  
Ultraviolet Observations ◽  
Different Levels ◽  
Good Agreement

<p>Identifying the plasmapause location is crucial for forecasting and modelling the radiation belts, as well as larger scale models of the magnetosphere. The ionospheric footpoints of the plasmapause are thought to map to the equatorward edge of the diffuse aurora, with the first direct observation of an undulation of the plasmapause boundary and corresponding auroral features reported by He et al. (2020). Despite the importance of the plasmapause location, we do not have global observations of the plasmapause location.</p><p>We provide a new statistical model of the plasmapause location determined from mapping the equatorward boundary of the observed auroral oval out to the inner magnetosphere. The model uses the equatorward boundary of the auroral oval determined from far-ultraviolet observations from the IMAGE spacecraft from Longden et al. (2010) to provide a statistical estimate of the plasmapause location for different levels of geomagnetic activity. Comparing the results of the statistical plasmapause model to other more direct measurements of the plasmapause shows a good agreement in the nightside local time sectors. </p><p>The results of this analysis show that the equatorward boundary of the auroral oval statistically maps closely to the plasmapause boundary the nightside sectors and provides an alternative use for global auroral image data from the upcoming SMILE mission. </p>

scholarly journals Substorm onset location and the equatorward boundary of the proton auroral oval

2002 ◽  
Vol 29 (24) ◽  
pp. 12-1-12-4 ◽  
Author(s):  
P. T. Jayachandran ◽  
J. W. MacDougall ◽  
D. R. Moorcroft ◽  
J.-P. St-Maurice ◽  
K. Liou ◽  
...  
Keyword(s):  
Auroral Oval ◽  
Substorm Onset ◽  
Equatorward Boundary ◽  
Onset Location
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