Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars
[1] We present several examples of reversed flow events (RFEs) from the cusp ionosphere. RFEs are 100–200 km wide flow channels opposing the background plasma convection. RFEs were discovered a few years ago by the incoherent scatter European Incoherent Scatter Svalbard Radar. In this paper we show...
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ftleicesterunfig:oai:figshare.com:article/10108457 2023-05-15T18:29:48+02:00 Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars K. Oksavik J. I. Moen E. H. Rekaa H. C. Carlson M. Lester 2011-12-03T00:00:00Z https://figshare.com/articles/journal_contribution/Reversed_flow_events_in_the_cusp_ionosphere_detected_by_SuperDARN_HF_radars/10108457 unknown 2381/11597 https://figshare.com/articles/journal_contribution/Reversed_flow_events_in_the_cusp_ionosphere_detected_by_SuperDARN_HF_radars/10108457 All Rights Reserved Uncategorized IR content Text Journal contribution 2011 ftleicesterunfig 2021-11-11T20:06:31Z [1] We present several examples of reversed flow events (RFEs) from the cusp ionosphere. RFEs are 100–200 km wide flow channels opposing the background plasma convection. RFEs were discovered a few years ago by the incoherent scatter European Incoherent Scatter Svalbard Radar. In this paper we show that coherent scatter Super Dual Auroral Radar Network (SuperDARN) HF radars can also see RFEs. We report a close relationship between RFEs and the development of HF backscatter power and spectral width. Wide spectra were seen near the edges of the RFEs (i.e., associated with the flow shear), and there was a significant increase in SuperDARN HF backscatter power when the RFE expanded. This increase in power is much faster than anticipated from the gradient drift instability alone, supporting the hypothesis that RFE flow shears foster rapid growth of Kelvin-Helmholtz instabilities. That decameter-scale irregularities form so rapidly should be an important guide to the development of instability theory for cascade of plasma irregularities from larger to smaller scale sizes. Other Non-Article Part of Journal/Newspaper Svalbard University of Leicester: Figshare Svalbard |
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University of Leicester: Figshare |
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ftleicesterunfig |
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Uncategorized IR content |
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Uncategorized IR content K. Oksavik J. I. Moen E. H. Rekaa H. C. Carlson M. Lester Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars |
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Uncategorized IR content |
description |
[1] We present several examples of reversed flow events (RFEs) from the cusp ionosphere. RFEs are 100–200 km wide flow channels opposing the background plasma convection. RFEs were discovered a few years ago by the incoherent scatter European Incoherent Scatter Svalbard Radar. In this paper we show that coherent scatter Super Dual Auroral Radar Network (SuperDARN) HF radars can also see RFEs. We report a close relationship between RFEs and the development of HF backscatter power and spectral width. Wide spectra were seen near the edges of the RFEs (i.e., associated with the flow shear), and there was a significant increase in SuperDARN HF backscatter power when the RFE expanded. This increase in power is much faster than anticipated from the gradient drift instability alone, supporting the hypothesis that RFE flow shears foster rapid growth of Kelvin-Helmholtz instabilities. That decameter-scale irregularities form so rapidly should be an important guide to the development of instability theory for cascade of plasma irregularities from larger to smaller scale sizes. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
K. Oksavik J. I. Moen E. H. Rekaa H. C. Carlson M. Lester |
author_facet |
K. Oksavik J. I. Moen E. H. Rekaa H. C. Carlson M. Lester |
author_sort |
K. Oksavik |
title |
Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars |
title_short |
Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars |
title_full |
Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars |
title_fullStr |
Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars |
title_full_unstemmed |
Reversed flow events in the cusp ionosphere detected by SuperDARN HF radars |
title_sort |
reversed flow events in the cusp ionosphere detected by superdarn hf radars |
publishDate |
2011 |
url |
https://figshare.com/articles/journal_contribution/Reversed_flow_events_in_the_cusp_ionosphere_detected_by_SuperDARN_HF_radars/10108457 |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
Svalbard |
genre_facet |
Svalbard |
op_relation |
2381/11597 https://figshare.com/articles/journal_contribution/Reversed_flow_events_in_the_cusp_ionosphere_detected_by_SuperDARN_HF_radars/10108457 |
op_rights |
All Rights Reserved |
_version_ |
1766213188204888064 |