Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations
International audience High-time resolution data from the two Iceland SuperDARN HF radars show very strong nightside convection activity during a prolonged period of low geomagnetic activity and northward interplanetary magnetic field (IMF). Flows bursts with velocities ranging from 0.8 to 1.7 km/s...
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ftunivnantes:oai:HAL:hal-00329243v1 2023-05-15T16:48:22+02:00 Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations Senior, C. Cerisier, J.-C. Rich, F. Lester, M. Parks, G. K. Centre d'étude des environnements terrestre et planétaires (CETP) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Air Force Research Laboratory (AFRL) United States Air Force (USAF) Radio and Space Plasma Physics Group Leicester (RSPP) University of Leicester Space Sciences Laboratory Berkeley (SSL) University of California Berkeley (UC Berkeley) University of California (UC)-University of California (UC) 2002 https://hal.science/hal-00329243 https://hal.science/hal-00329243/document https://hal.science/hal-00329243/file/angeo-20-771-2002.pdf en eng HAL CCSD European Geosciences Union hal-00329243 https://hal.science/hal-00329243 https://hal.science/hal-00329243/document https://hal.science/hal-00329243/file/angeo-20-771-2002.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00329243 Annales Geophysicae, 2002, 20 (6), pp.771-779 [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 2002 ftunivnantes 2023-02-08T04:19:41Z International audience High-time resolution data from the two Iceland SuperDARN HF radars show very strong nightside convection activity during a prolonged period of low geomagnetic activity and northward interplanetary magnetic field (IMF). Flows bursts with velocities ranging from 0.8 to 1.7 km/s are observed to propagate in the sunward direction with phase velocities up to 1.5 km/s. These bursts occur over several hours of MLT in the 20:00–01:00 MLT sector, in the evening-side sunward convection. Data from a simultaneous DMSP pass and POLAR UVI images show a very contracted polar cap and extended regions of auroral particle precipitation from the magnetospheric boundaries. A DMSP pass over the Iceland-West field-of-view while one of these sporadic bursts of enhanced flow is observed, indicates that the flow bursts appear within the plasma sheet and at its outward edge, which excludes Kelvin-Helmholtz instabilities at the magnetopause boundary as the generation mechanism. In the nightside region, the precipitation is more spot-like and the convection organizes itself as clockwise U-shaped structures. We interpret these flow bursts as the convective transport following plasma injection events from the tail into the night-side ionosphere. We show that during this period, where the IMF clock angle is around 70°, the dayside magnetosphere is not completely closed. Key words. Ionosphere (Auroral ionosphere; Ionospheremagnetosphere interactions; Particle precipitation) Article in Journal/Newspaper Iceland Université de Nantes: HAL-UNIV-NANTES |
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Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
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 Senior, C. Cerisier, J.-C. Rich, F. Lester, M. Parks, G. K. Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience High-time resolution data from the two Iceland SuperDARN HF radars show very strong nightside convection activity during a prolonged period of low geomagnetic activity and northward interplanetary magnetic field (IMF). Flows bursts with velocities ranging from 0.8 to 1.7 km/s are observed to propagate in the sunward direction with phase velocities up to 1.5 km/s. These bursts occur over several hours of MLT in the 20:00–01:00 MLT sector, in the evening-side sunward convection. Data from a simultaneous DMSP pass and POLAR UVI images show a very contracted polar cap and extended regions of auroral particle precipitation from the magnetospheric boundaries. A DMSP pass over the Iceland-West field-of-view while one of these sporadic bursts of enhanced flow is observed, indicates that the flow bursts appear within the plasma sheet and at its outward edge, which excludes Kelvin-Helmholtz instabilities at the magnetopause boundary as the generation mechanism. In the nightside region, the precipitation is more spot-like and the convection organizes itself as clockwise U-shaped structures. We interpret these flow bursts as the convective transport following plasma injection events from the tail into the night-side ionosphere. We show that during this period, where the IMF clock angle is around 70°, the dayside magnetosphere is not completely closed. Key words. Ionosphere (Auroral ionosphere; Ionospheremagnetosphere interactions; Particle precipitation) |
author2 |
Centre d'étude des environnements terrestre et planétaires (CETP) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) Air Force Research Laboratory (AFRL) United States Air Force (USAF) Radio and Space Plasma Physics Group Leicester (RSPP) University of Leicester Space Sciences Laboratory Berkeley (SSL) University of California Berkeley (UC Berkeley) University of California (UC)-University of California (UC) |
format |
Article in Journal/Newspaper |
author |
Senior, C. Cerisier, J.-C. Rich, F. Lester, M. Parks, G. K. |
author_facet |
Senior, C. Cerisier, J.-C. Rich, F. Lester, M. Parks, G. K. |
author_sort |
Senior, C. |
title |
Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations |
title_short |
Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations |
title_full |
Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations |
title_fullStr |
Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations |
title_full_unstemmed |
Strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: SuperDARN and satellite observations |
title_sort |
strong sunward propagating flow bursts in the night sector during quiet solar wind conditions: superdarn and satellite observations |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://hal.science/hal-00329243 https://hal.science/hal-00329243/document https://hal.science/hal-00329243/file/angeo-20-771-2002.pdf |
genre |
Iceland |
genre_facet |
Iceland |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00329243 Annales Geophysicae, 2002, 20 (6), pp.771-779 |
op_relation |
hal-00329243 https://hal.science/hal-00329243 https://hal.science/hal-00329243/document https://hal.science/hal-00329243/file/angeo-20-771-2002.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766038467421143040 |