High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater
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...
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ftleicesterunfig:oai:figshare.com:article/10115357 2023-05-15T16:04:48+02:00 High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater T. K. Yeoman D. M. Wright T. R. Robinson J. A. Davies M. Rietveld 1997-06-01T00:00:00Z https://figshare.com/articles/journal_contribution/High_spatial_and_temporal_resolution_observations_of_an_impulse-driven_field_line_resonance_in_radar_backscatter_artificially_generated_with_the_Troms_heater/10115357 unknown 2381/19725 https://figshare.com/articles/journal_contribution/High_spatial_and_temporal_resolution_observations_of_an_impulse-driven_field_line_resonance_in_radar_backscatter_artificially_generated_with_the_Troms_heater/10115357 All Rights Reserved Uncategorized Science & Technology Physical Sciences Astronomy & Astrophysics Geosciences Multidisciplinary Meteorology & Atmospheric Sciences Geology GEOMAGNETIC-PULSATIONS ULF WAVES PI-2 PULSATIONS PI2 PULSATIONS CAVITY MODES HF RADAR MAGNETOSPHERE PROPAGATION EXCITATION IONOSPHERE Text Journal contribution 1997 ftleicesterunfig 2021-11-11T20:04:58Z 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. Other Non-Article Part of Journal/Newspaper EISCAT Tromsø University of Leicester: Figshare Tromsø |
institution |
Open Polar |
collection |
University of Leicester: Figshare |
op_collection_id |
ftleicesterunfig |
language |
unknown |
topic |
Uncategorized Science & Technology Physical Sciences Astronomy & Astrophysics Geosciences Multidisciplinary Meteorology & Atmospheric Sciences Geology GEOMAGNETIC-PULSATIONS ULF WAVES PI-2 PULSATIONS PI2 PULSATIONS CAVITY MODES HF RADAR MAGNETOSPHERE PROPAGATION EXCITATION IONOSPHERE |
spellingShingle |
Uncategorized Science & Technology Physical Sciences Astronomy & Astrophysics Geosciences Multidisciplinary Meteorology & Atmospheric Sciences Geology GEOMAGNETIC-PULSATIONS ULF WAVES PI-2 PULSATIONS PI2 PULSATIONS CAVITY MODES HF RADAR MAGNETOSPHERE PROPAGATION EXCITATION IONOSPHERE T. K. Yeoman D. M. Wright T. R. Robinson J. A. Davies M. Rietveld High spatial and temporal resolution observations of an impulse-driven field line resonance in radar backscatter artificially generated with the Tromsø heater |
topic_facet |
Uncategorized Science & Technology Physical Sciences Astronomy & Astrophysics Geosciences Multidisciplinary Meteorology & Atmospheric Sciences Geology GEOMAGNETIC-PULSATIONS ULF WAVES PI-2 PULSATIONS PI2 PULSATIONS CAVITY MODES HF RADAR MAGNETOSPHERE PROPAGATION EXCITATION IONOSPHERE |
description |
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. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
T. K. Yeoman D. M. Wright T. R. Robinson J. A. Davies M. Rietveld |
author_facet |
T. K. Yeoman D. M. Wright T. R. Robinson J. A. Davies M. Rietveld |
author_sort |
T. K. Yeoman |
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 |
publishDate |
1997 |
url |
https://figshare.com/articles/journal_contribution/High_spatial_and_temporal_resolution_observations_of_an_impulse-driven_field_line_resonance_in_radar_backscatter_artificially_generated_with_the_Troms_heater/10115357 |
geographic |
Tromsø |
geographic_facet |
Tromsø |
genre |
EISCAT Tromsø |
genre_facet |
EISCAT Tromsø |
op_relation |
2381/19725 https://figshare.com/articles/journal_contribution/High_spatial_and_temporal_resolution_observations_of_an_impulse-driven_field_line_resonance_in_radar_backscatter_artificially_generated_with_the_Troms_heater/10115357 |
op_rights |
All Rights Reserved |
_version_ |
1766400429222002688 |