scholarly journals Investigating Transport and Dissipation in the Subauroral E Region With Ionospheric Modification Experiments and Very High Frequency Radar Backscatter

Radio Science ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 245-253 ◽  
Author(s):  
D. L. Hysell ◽  
J. Munk ◽  
M. McCarrick
2021 ◽  
Author(s):  
Wenjie Sun ◽  
Baiqi Ning ◽  
Lianhuan Hu ◽  
Xiukuan Zhao ◽  
Guozhu Li

<p>Early and recent observations suggested that E-region field aligned irregularities (FAIs) related closely to the sporadic E (Es) layer of the ionosphere. The Sanya (18.3 ºN, 109.6 ºE) very high frequency (VHF) radar can operate at ionospheric irregularities mode for the detection of 3-m scale FAIs. The development of a portable digital ionosonde (PDI) which is collocated with the Sanya VHF radar can operate with temporal periods down to 1 minute, facilitating the capability of capturing the fast evolution of Es structures. But the low spatial resolution of the two kinds of instruments makes it difficult to depict the horizontal morphology of the Es structures and E-region FAIs. Since the capability of ground-based GNSS in strong Es detection was presented, it serves as a perfect supplement for the investigation of E region of the ionosphere. So comprehensive observation with multi kinds of instruments makes it possible to reveal the relationship and mechanisms of Es and E-region FAIs.</p><p>A complex daytime sporadic E (Es) case with extremely high critical frequency (foEs) was observed over the low latitude of China on 19 May 2018. Simultaneous observational results from two very high frequency (VHF) radars, two ionosondes, and multiple Global Navigation Satellite System total electron content and scintillation receivers are analyzed to investigate the evolution of the complex Es occurrence, which consisted of a relatively weak ambient Es layer (foEs < 8 MHz) and band-like strong Es structures (foEs > 17 MHz) drifting from higher latitude. The strong Es structures elongated more than 500 km in the northwest-southeast direction, drifted southwestward at a speed of ~65 m/s. VHF radar backscatter echoes were generated when the strong Es structures passed the radar field of view, with different echo patterns due to different radar and antenna configurations. No VHF radar backscatter echo was associated with the ambient Es layer.</p>


1953 ◽  
Vol 31 (2) ◽  
pp. 171-181 ◽  
Author(s):  
D. W. R. McKinley ◽  
Peter M. Millman

In the course of the Ottawa meteor program some unusual echoes have been detected on 33 Mc. Echoes from the aurora are discussed and correlated with visual observations. Two mechanisms of radio reflections from the aurora have been proposed but the data here presented are insufficient to favor one over the other. On Aug. 4, 1948, six extremely long duration meteor echoes were observed which may have been due to abnormal ionospheric conditions. From time to time since August, 1948, a weak semipermanent echo has been recorded, usually appearing at a range of about 80 km., and enduring up to an hour. It is suggested that this echo is due to back-scatter from the same sources in the lower E-region that are presumed to be responsible for long-range very high frequency propagation.


2014 ◽  
Vol 8 (9) ◽  
pp. 1035-1041 ◽  
Author(s):  
Zhen‐hai Xu ◽  
Jia‐ni Wu ◽  
Ziyuan Xiong ◽  
Shun‐ping Xiao

2017 ◽  
Vol 11 (4) ◽  
pp. 616-620 ◽  
Author(s):  
Haiyin Qing ◽  
Yenhsyang Chu ◽  
Zhengyu Zhao ◽  
Chinglun Su ◽  
Chen Zhou ◽  
...  

1954 ◽  
Vol 32 (5) ◽  
pp. 326-329 ◽  
Author(s):  
J. H. Meek ◽  
A. G. McNamara

A comparison of simultaneous data on the visible aurora, the earth's magnetic field variation, vertical and oblique ionosonde echoes, and very-high-frequency radar echoes has been made. Long-range high-frequency and very-high-frequency radio echoes do not appear to correlate individually. Reflections are observed, however, on both frequency ranges coincident with the appearance of low elevation auroral arcs, which are associated with magnetic bays.


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