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Global Imaging of Polar Cap Patches With Dual Airglow Imagers [PDF]

Geophysical Research Letters, 2014
During a 2 h interval from 2240 to 2440 UT on 12 November 2012, regions of increased 630.0 nm airglow emissions were simultaneously detected by dual all‐sky imagers in the polar cap, one at Longyearbyen, Norway (78.1°N, 15.5°E) and the other at Resolute Bay, Canada (74.7°N, 265.1°E). The Resolute Bay incoherent scatter radar observed clear enhancements
Keisuke Hosokawa, Satoshi Taguchi, Yuichi Ōtsuka   +2 more
exaly   +2 more sources

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On the Creation, Depletion, and End of Life of Polar Cap Patches

2022
Ionospheric convection patterns from the Super Dual Auroral Radar Network are used to determine the trajectories, transit times and decay rates of three polar cap patches from their creation in the dayside polar cap ionosphere to their end of life on the nightside.
Nina Kristine Eriksen, Dag Lorentzen, Lisa Jane Baddeley, Kjellmar Oksavik, Keisuke Hosokawa, Kazuo Shiokawa, Emma Christine Bland, Larry J. Paxton, Yongliang Zhang, Kathryn McWilliam, Tim K. Yeoman   +10 more
openaire   +1 more source

Direct Observations of the Evolution of Polar Cap Ionization Patches

Science, 2013
Patchy Polar Cap Patches of enhanced density plasma in the polar ionosphere (or polar cap patches) disturb radio communications and satellite positioning at high latitudes during magnetospheric storms. Using data from Global Positioning System satellites and a high-frequency radar network,
Qing-He, Zhang, Bei-Chen, Zhang, Michael, Lockwood, Hong-Qiao, Hu, Jøran, Moen, J Michael, Ruohoniemi, Evan G, Thomas, Shun-Rong, Zhang, Hui-Gen, Yang, Rui-Yuan, Liu, Kathryn A, McWilliams, Joseph B H, Baker   +11 more
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Can Throat Auroras Create Polar Cap Patches？

2023
Throat auroras and polar cap patches are common phenomena in the polar ionosphere. An observation campaign was organized, with all-sky imagers at Yellow River Station in Ny-Ålesund in Svalbard, the EISCAT Svalbard Radar, and coordinated low-altitude spacecraft observations.
Duan Zhang, Qinghe Zhang, Kjellmar Oksavik, Tong Xu, Zanyang Xing, Larry Lyons, Desheng Han, Hongbo Zhang, Yuzhang Ma, Zejun Hu, Jianjun Liu, Yong Wang, Xiangyu Wang   +12 more
openaire   +1 more source

Velocity fluctuations associated with polar cap patches

Radio Science, 1996
The digital ionosonde technique has been used to measure the convection in the vicinity of polar cap patches. Two types of velocity fluctuations were seen: (1) parallel fluctuations which are a slowing down and speeding up of the convection without a change in direction, and (2) perpendicular fluctuations which are perpendicular to the average ...
J. W. MacDougall, I. F. Grant, A. Hamza
openaire   +1 more source

Airglow Patches in the Polar Cap Region: A Review

Space Science Reviews, 2019
Polar cap airglow patches have been known as regions of enhanced 630.0 nm airglow detected by ground-based all-sky imagers at the polar cap latitudes well inside the main auroral oval. Although they were already recognized almost four decades ago as counterparts of polar cap (plasma density) patches, such airglow observations had not been utilized ...
Keisuke Hosokawa, Ying Zou, Yukitoshi Nishimura   +2 more
openaire   +1 more source

Signatures of polar cap patches in ground ionosonde data

Radio Science, 1997
The interpretation of localized density structures in the high‐latitude ionosphere as observed by ground ionosondes is a task that is complicated by the complexity of those structures and by the variety of processes that ionosonde waves undergo. To aid interpretation, we have performed a first‐order analysis of the shapes of traces seen in ionosonde ...
H. G. James, J. W. MacDougall
openaire   +1 more source

Earth's Ion Upflow Associated With Polar Cap Patches: Global and in Situ Observations [PDF]

Geophysical Research Letters, 2016
AbstractWe report simultaneous global monitoring of a patch of ionization and in situ observation of ion upflow at the center of the polar cap region during a geomagnetic storm. Our observations indicate strong fluxes of upwelling O+ ions originating from frictional heating produced by rapid antisunward flow of the plasma patch. The statistical results
Yu-Zhang Ma, Mark Lester, Evan G Thomas
exaly   +3 more sources

Polar-cap patches as a source of Doppler spread in the polar-cap: a case study

• Doppler curve for ePOP-RRI-CLY conjunction shows dramatic variability in ~500 Hz, especially during 100-250 s elapsed. • Received signal power also shows an eastward shift in the expected position of CLY's peak power. • Consistent with QAN-ALE deviations in Fig. 2.
Gareth William Perry, Leslie Lamarche, Olusegun Jonah, Taylor Cameron   +3 more
openaire   +1 more source

Modeling the formation of polar cap patches using large plasma flows

Radio Science, 1996
Recent measurements made with the Sondrestrom incoherent scatter radar have indicated that the formation of polar cap patches can be closely associated with the flow of a large plasma jet. In this paper, we report the results of a numerical study to investigate the role of plasma jets on patch formation, to determine the temporal evolution of the ...
C. E. Valladares, D. T. Decker, R. Sheehan, D. N. Anderson   +3 more
openaire   +1 more source