The effect of electron bite-outs on artificial electron heating and the PMSE overshoot
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 (...
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ftdoajarticles:oai:doaj.org/article:3b06aba766e2416c8c01c63234838ad7 2023-05-15T16:04:42+02:00 The effect of electron bite-outs on artificial electron heating and the PMSE overshoot M. Kassa O. Havnes E. Belova 2005-12-01T00:00:00Z https://doi.org/10.5194/angeo-23-3633-2005 https://doaj.org/article/3b06aba766e2416c8c01c63234838ad7 EN eng Copernicus Publications https://www.ann-geophys.net/23/3633/2005/angeo-23-3633-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-3633-2005 0992-7689 1432-0576 https://doaj.org/article/3b06aba766e2416c8c01c63234838ad7 Annales Geophysicae, Vol 23, Pp 3633-3643 (2005) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2005 ftdoajarticles https://doi.org/10.5194/angeo-23-3633-2005 2022-12-30T22:40:33Z 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 it. On the third day there ... Article in Journal/Newspaper EISCAT Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 23 12 3633 3643 |
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Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
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Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 M. Kassa O. Havnes E. Belova The effect of electron bite-outs on artificial electron heating and the PMSE overshoot |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
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 it. On the third day there ... |
format |
Article in Journal/Newspaper |
author |
M. Kassa O. Havnes E. Belova |
author_facet |
M. Kassa O. Havnes E. Belova |
author_sort |
M. Kassa |
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 |
Copernicus Publications |
publishDate |
2005 |
url |
https://doi.org/10.5194/angeo-23-3633-2005 https://doaj.org/article/3b06aba766e2416c8c01c63234838ad7 |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Vol 23, Pp 3633-3643 (2005) |
op_relation |
https://www.ann-geophys.net/23/3633/2005/angeo-23-3633-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-3633-2005 0992-7689 1432-0576 https://doaj.org/article/3b06aba766e2416c8c01c63234838ad7 |
op_doi |
https://doi.org/10.5194/angeo-23-3633-2005 |
container_title |
Annales Geophysicae |
container_volume |
23 |
container_issue |
12 |
container_start_page |
3633 |
op_container_end_page |
3643 |
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