The effect of electron bite-outs on artificial electron heating and the PMSE overshoot

International audience We have considered the effect that a local reduction in the electron density (an electron bite-out), caused by electron absorption on to dust particles, can have on the artificial electron heating in the height region between 80 to 90km, where noctilucent clouds (NLC) and the...

Full description

Bibliographic Details
Main Authors: Kassa, M., Havnes, O., Belova, E.
Other Authors: Department of Physics, University of Tromsø (UiT), UNIS, UniS, Swedish Institute of Space Physics Kiruna (IRF)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2005
Subjects:
Online Access:https://hal.science/hal-00318092
https://hal.science/hal-00318092/document
https://hal.science/hal-00318092/file/angeo-23-3633-2005.pdf
id ftccsdartic:oai:HAL:hal-00318092v1
record_format openpolar
spelling ftccsdartic:oai:HAL:hal-00318092v1 2023-11-12T04:16:36+01:00 The effect of electron bite-outs on artificial electron heating and the PMSE overshoot Kassa, M. Havnes, O. Belova, E. Department of Physics University of Tromsø (UiT) UNIS UniS Swedish Institute of Space Physics Kiruna (IRF) 2005-12-23 https://hal.science/hal-00318092 https://hal.science/hal-00318092/document https://hal.science/hal-00318092/file/angeo-23-3633-2005.pdf en eng HAL CCSD European Geosciences Union hal-00318092 https://hal.science/hal-00318092 https://hal.science/hal-00318092/document https://hal.science/hal-00318092/file/angeo-23-3633-2005.pdf info:eu-repo/semantics/OpenAccess ISSN: 0992-7689 EISSN: 1432-0576 Annales Geophysicae https://hal.science/hal-00318092 Annales Geophysicae, 2005, 23 (12), pp.3633-3643 [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 2005 ftccsdartic 2023-10-21T23:06:49Z International audience We have considered the effect that a local reduction in the electron density (an electron bite-out), caused by electron absorption on to dust particles, can have on the artificial electron heating in the height region between 80 to 90km, where noctilucent clouds (NLC) and the radar phenomenon PMSE (Polar Mesospheric Summer Echoes) are observed. With an electron density profile without bite-outs, the heated electron temperature T e, hot will generally decrease smoothly with height in the PMSE region or there may be no significant heating effect present. Within a bite-out T e, hot will decrease less rapidly and can even increase slightly with height if the bite-out is strong. We have looked at recent observations of PMSE which are affected by artificial electron heating, with a heater cycling producing the new overshoot effect. According to the theory for the PMSE overshoot the fractional increase in electron temperature T e, hot / T i , where T i is the unaffected ion temperature=neutral temperature, can be found from the reduction in PMSE intensity as the heater is switched on. We have looked at results from four days of observations with the EISCAT VHF radar (224 MHz), together with the EISCAT heating facility. We find support for the PMSE overshoot and heating model from a sequence of observations during one of the days where the heater transmitter power is varied from cycle to cycle and where the calculated T e, hot / T i is found to vary in proportion to the transmitter power. We also looked for signatures of electron bite-outs by examining the variation of T e, hot / T i with height for the three other days. We find that the height variation of T e, hot / T i is very different on the three days. On one of the days we see typically that this ratio can increase with height, showing the presence of a bite-out, while on the next day the heating factor mainly decreases with height, indicating that the fractional amount of dust is low, so that the electron density is hardly affected by ... Article in Journal/Newspaper EISCAT Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
institution Open Polar
collection Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
op_collection_id ftccsdartic
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
Kassa, M.
Havnes, O.
Belova, E.
The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
topic_facet [SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences
description International audience We have considered the effect that a local reduction in the electron density (an electron bite-out), caused by electron absorption on to dust particles, can have on the artificial electron heating in the height region between 80 to 90km, where noctilucent clouds (NLC) and the radar phenomenon PMSE (Polar Mesospheric Summer Echoes) are observed. With an electron density profile without bite-outs, the heated electron temperature T e, hot will generally decrease smoothly with height in the PMSE region or there may be no significant heating effect present. Within a bite-out T e, hot will decrease less rapidly and can even increase slightly with height if the bite-out is strong. We have looked at recent observations of PMSE which are affected by artificial electron heating, with a heater cycling producing the new overshoot effect. According to the theory for the PMSE overshoot the fractional increase in electron temperature T e, hot / T i , where T i is the unaffected ion temperature=neutral temperature, can be found from the reduction in PMSE intensity as the heater is switched on. We have looked at results from four days of observations with the EISCAT VHF radar (224 MHz), together with the EISCAT heating facility. We find support for the PMSE overshoot and heating model from a sequence of observations during one of the days where the heater transmitter power is varied from cycle to cycle and where the calculated T e, hot / T i is found to vary in proportion to the transmitter power. We also looked for signatures of electron bite-outs by examining the variation of T e, hot / T i with height for the three other days. We find that the height variation of T e, hot / T i is very different on the three days. On one of the days we see typically that this ratio can increase with height, showing the presence of a bite-out, while on the next day the heating factor mainly decreases with height, indicating that the fractional amount of dust is low, so that the electron density is hardly affected by ...
author2 Department of Physics
University of Tromsø (UiT)
UNIS
UniS
Swedish Institute of Space Physics Kiruna (IRF)
format Article in Journal/Newspaper
author Kassa, M.
Havnes, O.
Belova, E.
author_facet Kassa, M.
Havnes, O.
Belova, E.
author_sort Kassa, M.
title The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
title_short The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
title_full The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
title_fullStr The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
title_full_unstemmed The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
title_sort effect of electron bite-outs on artificial electron heating and the pmse overshoot
publisher HAL CCSD
publishDate 2005
url https://hal.science/hal-00318092
https://hal.science/hal-00318092/document
https://hal.science/hal-00318092/file/angeo-23-3633-2005.pdf
genre EISCAT
genre_facet EISCAT
op_source ISSN: 0992-7689
EISSN: 1432-0576
Annales Geophysicae
https://hal.science/hal-00318092
Annales Geophysicae, 2005, 23 (12), pp.3633-3643
op_relation hal-00318092
https://hal.science/hal-00318092
https://hal.science/hal-00318092/document
https://hal.science/hal-00318092/file/angeo-23-3633-2005.pdf
op_rights info:eu-repo/semantics/OpenAccess
_version_ 1782333686359785472