Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars
International audience Meteor head echo altitude distributions have been derived from data collected with the EISCAT VHF (224MHz) and UHF (930MHz) high-power, large-aperture (HPLA) radars. At the high-altitude end, the distributions cut off abruptly in a manner reminiscent of the trail echo height c...
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ftinsu:oai:HAL:hal-00317334v1 2023-11-12T04:16:36+01:00 Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars Westman, A. Wannberg, G. Pellinen-Wannberg, A. EISCAT Scientific Association Swedish Institute of Space Physics Kiruna (IRF) 2004-04-08 https://hal.science/hal-00317334 https://hal.science/hal-00317334/document https://hal.science/hal-00317334/file/angeo-22-1575-2004.pdf en eng HAL CCSD European Geosciences Union hal-00317334 https://hal.science/hal-00317334 https://hal.science/hal-00317334/document https://hal.science/hal-00317334/file/angeo-22-1575-2004.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00317334 Annales Geophysicae, 2004, 22 (5), pp.1575-1584 [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 2004 ftinsu 2023-10-25T16:25:17Z International audience Meteor head echo altitude distributions have been derived from data collected with the EISCAT VHF (224MHz) and UHF (930MHz) high-power, large-aperture (HPLA) radars. At the high-altitude end, the distributions cut off abruptly in a manner reminiscent of the trail echo height ceiling effect observed with classical meteor radars. The target dimensions are shown to be much smaller than both the VHF and the UHF probing wavelengths, but the cutoff heights for the two systems are still clearly different, the VHF cutoff being located several km above the UHF one. A single-collision meteor-atmosphere interaction model is used to demonstrate that meteors in the (1.3?7.2) µ g mass range will ionise such that critical electron density at 224MHz is first reached at or around the VHF cutoff altitude and critical density at 930MHz will be reached at the UHF cutoff altitude. The observed seasonal variation in the cutoff altitudes is shown to be a function of the seasonal variation of atmospheric density with altitude. Assuming that the electron density required for detection is in the order of the critical density, the abrupt altitude cutoffs can be explained as a consequence of the micrometeoroid joint size-speed distribution dropping off so fast at the large-mass, high-velocity end that above a certain altitude the number of detectable events becomes vanishingly small. Conversely, meteors at the low-mass end of the distribution will be gradually retarded such that the ionisation they generate never reaches critical density. These particles will remain unobservable. Article in Journal/Newspaper EISCAT Institut national des sciences de l'Univers: HAL-INSU |
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 Westman, A. Wannberg, G. Pellinen-Wannberg, A. Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Meteor head echo altitude distributions have been derived from data collected with the EISCAT VHF (224MHz) and UHF (930MHz) high-power, large-aperture (HPLA) radars. At the high-altitude end, the distributions cut off abruptly in a manner reminiscent of the trail echo height ceiling effect observed with classical meteor radars. The target dimensions are shown to be much smaller than both the VHF and the UHF probing wavelengths, but the cutoff heights for the two systems are still clearly different, the VHF cutoff being located several km above the UHF one. A single-collision meteor-atmosphere interaction model is used to demonstrate that meteors in the (1.3?7.2) µ g mass range will ionise such that critical electron density at 224MHz is first reached at or around the VHF cutoff altitude and critical density at 930MHz will be reached at the UHF cutoff altitude. The observed seasonal variation in the cutoff altitudes is shown to be a function of the seasonal variation of atmospheric density with altitude. Assuming that the electron density required for detection is in the order of the critical density, the abrupt altitude cutoffs can be explained as a consequence of the micrometeoroid joint size-speed distribution dropping off so fast at the large-mass, high-velocity end that above a certain altitude the number of detectable events becomes vanishingly small. Conversely, meteors at the low-mass end of the distribution will be gradually retarded such that the ionisation they generate never reaches critical density. These particles will remain unobservable. |
author2 |
EISCAT Scientific Association Swedish Institute of Space Physics Kiruna (IRF) |
format |
Article in Journal/Newspaper |
author |
Westman, A. Wannberg, G. Pellinen-Wannberg, A. |
author_facet |
Westman, A. Wannberg, G. Pellinen-Wannberg, A. |
author_sort |
Westman, A. |
title |
Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars |
title_short |
Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars |
title_full |
Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars |
title_fullStr |
Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars |
title_full_unstemmed |
Meteor head echo altitude distributions and the height cutoff effect studied with the EISCAT HPLA UHF and VHF radars |
title_sort |
meteor head echo altitude distributions and the height cutoff effect studied with the eiscat hpla uhf and vhf radars |
publisher |
HAL CCSD |
publishDate |
2004 |
url |
https://hal.science/hal-00317334 https://hal.science/hal-00317334/document https://hal.science/hal-00317334/file/angeo-22-1575-2004.pdf |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00317334 Annales Geophysicae, 2004, 22 (5), pp.1575-1584 |
op_relation |
hal-00317334 https://hal.science/hal-00317334 https://hal.science/hal-00317334/document https://hal.science/hal-00317334/file/angeo-22-1575-2004.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782333670699302912 |