STARE velocity at large flow angles: is it related to the ion acoustic speed?
International audience The electron drift and ion-acoustic speed in the E region inferred from EISCAT measurements are compared with concurrent STARE radar velocity data to investigate a recent hypothesis by Bahcivan et al. (2005), that the electrojet irregularity velocity at large flow angles is si...
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ftinsu:oai:HAL:hal-00317999v1 2024-04-28T08:17:32+00:00 STARE velocity at large flow angles: is it related to the ion acoustic speed? Uspensky, M. V. Koustov, A. V. Nozawa, S. Finnish Meteorological Institute (FMI) Institute of Space and Atmospheric Studies Saskatoon (ISAS) Department of Physics and Engineering Physics Saskatoon University of Saskatchewan Saskatoon (U of S)-University of Saskatchewan Saskatoon (U of S) Solar-Terrestrial Environment Laboratory Nagoya (STEL) Nagoya University 2006-05-19 https://hal.science/hal-00317999 https://hal.science/hal-00317999/document https://hal.science/hal-00317999/file/angeo-24-873-2006.pdf en eng HAL CCSD European Geosciences Union hal-00317999 https://hal.science/hal-00317999 https://hal.science/hal-00317999/document https://hal.science/hal-00317999/file/angeo-24-873-2006.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00317999 Annales Geophysicae, 2006, 24 (3), pp.873-885 [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2006 ftinsu 2024-04-05T00:38:11Z International audience The electron drift and ion-acoustic speed in the E region inferred from EISCAT measurements are compared with concurrent STARE radar velocity data to investigate a recent hypothesis by Bahcivan et al. (2005), that the electrojet irregularity velocity at large flow angles is simply the product of the ion-acoustic speed and the cosine of an angle between the electron flow and the irregularity propagation direction. About 3000 measurements for flow angles of 50°?70° and electron drifts of 400?1500 m/s are considered. It is shown that the correlation coefficient and the slope of the best linear fit line between the predicted STARE velocity (based solely on EISCAT data and the hypothesis of Bahcivan et al. (2005)) and the measured one are both of the order of ~0.4. Velocity predictions are somewhat better if one assumes that the irregularity phase velocity is the line-of-sight component of the E × B drift scaled down by a factor ~0.6 due to off-orthogonality of irregularity propagation (nonzero effective aspect angles of STARE observations). Article in Journal/Newspaper EISCAT Institut national des sciences de l'Univers: HAL-INSU |
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Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Uspensky, M. V. Koustov, A. V. Nozawa, S. STARE velocity at large flow angles: is it related to the ion acoustic speed? |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The electron drift and ion-acoustic speed in the E region inferred from EISCAT measurements are compared with concurrent STARE radar velocity data to investigate a recent hypothesis by Bahcivan et al. (2005), that the electrojet irregularity velocity at large flow angles is simply the product of the ion-acoustic speed and the cosine of an angle between the electron flow and the irregularity propagation direction. About 3000 measurements for flow angles of 50°?70° and electron drifts of 400?1500 m/s are considered. It is shown that the correlation coefficient and the slope of the best linear fit line between the predicted STARE velocity (based solely on EISCAT data and the hypothesis of Bahcivan et al. (2005)) and the measured one are both of the order of ~0.4. Velocity predictions are somewhat better if one assumes that the irregularity phase velocity is the line-of-sight component of the E × B drift scaled down by a factor ~0.6 due to off-orthogonality of irregularity propagation (nonzero effective aspect angles of STARE observations). |
author2 |
Finnish Meteorological Institute (FMI) Institute of Space and Atmospheric Studies Saskatoon (ISAS) Department of Physics and Engineering Physics Saskatoon University of Saskatchewan Saskatoon (U of S)-University of Saskatchewan Saskatoon (U of S) Solar-Terrestrial Environment Laboratory Nagoya (STEL) Nagoya University |
format |
Article in Journal/Newspaper |
author |
Uspensky, M. V. Koustov, A. V. Nozawa, S. |
author_facet |
Uspensky, M. V. Koustov, A. V. Nozawa, S. |
author_sort |
Uspensky, M. V. |
title |
STARE velocity at large flow angles: is it related to the ion acoustic speed? |
title_short |
STARE velocity at large flow angles: is it related to the ion acoustic speed? |
title_full |
STARE velocity at large flow angles: is it related to the ion acoustic speed? |
title_fullStr |
STARE velocity at large flow angles: is it related to the ion acoustic speed? |
title_full_unstemmed |
STARE velocity at large flow angles: is it related to the ion acoustic speed? |
title_sort |
stare velocity at large flow angles: is it related to the ion acoustic speed? |
publisher |
HAL CCSD |
publishDate |
2006 |
url |
https://hal.science/hal-00317999 https://hal.science/hal-00317999/document https://hal.science/hal-00317999/file/angeo-24-873-2006.pdf |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00317999 Annales Geophysicae, 2006, 24 (3), pp.873-885 |
op_relation |
hal-00317999 https://hal.science/hal-00317999 https://hal.science/hal-00317999/document https://hal.science/hal-00317999/file/angeo-24-873-2006.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1797582067235553280 |