High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater
International audience The CUTLASS Finland HF radar has been operated in conjunction with the EISCAT Tromsø RF ionospheric heater facility to examine a ULF wave characteristic of the development of a field line resonance (FLR) driven by a cavity mode caused by a magnetospheric impulse. When the heat...
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ftinsu:oai:HAL:hal-00316254v1 2023-11-12T04:16:38+01:00 High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater Yeoman, T. K. Wright, D. M. Robinson, T. R. Davies, J. A. Rietveld, M. Department of Physics and Astronomy Leicester University of Leicester Max-Planck-Institut für Aeronomie (MPI Aeronomie) Max-Planck-Gesellschaft 1997 https://hal.science/hal-00316254 https://hal.science/hal-00316254/document https://hal.science/hal-00316254/file/angeo-15-634-1997.pdf en eng HAL CCSD European Geosciences Union hal-00316254 https://hal.science/hal-00316254 https://hal.science/hal-00316254/document https://hal.science/hal-00316254/file/angeo-15-634-1997.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316254 Annales Geophysicae, 1997, 15 (6), pp.634-644 [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 1997 ftinsu 2023-10-25T16:25:42Z International audience The CUTLASS Finland HF radar has been operated in conjunction with the EISCAT Tromsø RF ionospheric heater facility to examine a ULF wave characteristic of the development of a field line resonance (FLR) driven by a cavity mode caused by a magnetospheric impulse. When the heater is on, striating the ionosphere with field-aligned ionospheric electron density irregularities, a large enough radar target is generated to allow post-integration over only 1 second. When combined with 15 km range gates, this gives radar measurements of a naturally occurring ULF wave at a far better temporal and spatial resolution than has been achieved previously. The time-dependent signature of the ULF wave has been examined as it evolves from a large-scale cavity resonance, through a transient where the wave period was latitude-dependent and the oscillation had the characteristics of freely ringing field lines, and finally to a very narrow, small-scale local field line resonance. The resonance width of the FLR is only 60 km and this is compared with previous observations and theory. The FLR wave signature is strongly attenuated in the ground magnetometer data. The characterisation of the impulse driven FLR was only achieved very crudely with the ground magnetometer data and, in fact, an accurate determination of the properties of the cavity and field line resonant systems challenges the currently available limitations of ionospheric radar techniques. The combination of the latest ionospheric radars and facilities such as the Tromsø ionospheric heater can result in a powerful new tool for geophysical research. Article in Journal/Newspaper EISCAT Tromsø Institut national des sciences de l'Univers: HAL-INSU Tromsø |
institution |
Open Polar |
collection |
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 Yeoman, T. K. Wright, D. M. Robinson, T. R. Davies, J. A. Rietveld, M. High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience The CUTLASS Finland HF radar has been operated in conjunction with the EISCAT Tromsø RF ionospheric heater facility to examine a ULF wave characteristic of the development of a field line resonance (FLR) driven by a cavity mode caused by a magnetospheric impulse. When the heater is on, striating the ionosphere with field-aligned ionospheric electron density irregularities, a large enough radar target is generated to allow post-integration over only 1 second. When combined with 15 km range gates, this gives radar measurements of a naturally occurring ULF wave at a far better temporal and spatial resolution than has been achieved previously. The time-dependent signature of the ULF wave has been examined as it evolves from a large-scale cavity resonance, through a transient where the wave period was latitude-dependent and the oscillation had the characteristics of freely ringing field lines, and finally to a very narrow, small-scale local field line resonance. The resonance width of the FLR is only 60 km and this is compared with previous observations and theory. The FLR wave signature is strongly attenuated in the ground magnetometer data. The characterisation of the impulse driven FLR was only achieved very crudely with the ground magnetometer data and, in fact, an accurate determination of the properties of the cavity and field line resonant systems challenges the currently available limitations of ionospheric radar techniques. The combination of the latest ionospheric radars and facilities such as the Tromsø ionospheric heater can result in a powerful new tool for geophysical research. |
author2 |
Department of Physics and Astronomy Leicester University of Leicester Max-Planck-Institut für Aeronomie (MPI Aeronomie) Max-Planck-Gesellschaft |
format |
Article in Journal/Newspaper |
author |
Yeoman, T. K. Wright, D. M. Robinson, T. R. Davies, J. A. Rietveld, M. |
author_facet |
Yeoman, T. K. Wright, D. M. Robinson, T. R. Davies, J. A. Rietveld, M. |
author_sort |
Yeoman, T. K. |
title |
High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
title_short |
High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
title_full |
High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
title_fullStr |
High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
title_full_unstemmed |
High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
title_sort |
high spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the tromsø heater |
publisher |
HAL CCSD |
publishDate |
1997 |
url |
https://hal.science/hal-00316254 https://hal.science/hal-00316254/document https://hal.science/hal-00316254/file/angeo-15-634-1997.pdf |
geographic |
Tromsø |
geographic_facet |
Tromsø |
genre |
EISCAT Tromsø |
genre_facet |
EISCAT Tromsø |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00316254 Annales Geophysicae, 1997, 15 (6), pp.634-644 |
op_relation |
hal-00316254 https://hal.science/hal-00316254 https://hal.science/hal-00316254/document https://hal.science/hal-00316254/file/angeo-15-634-1997.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782333711538192384 |