Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths
On 5 July 2005, simultaneous observations of Polar Mesosphere Summer Echoes (PMSE) were made using the EISCAT VHF (224 MHz) and UHF (933 MHz) radars located near Tromsø, Norway and the ALWIN VHF radar (53.5 MHz) situated on Andøya, 120 km SW of the EISCAT site. During the short interval from 12:20 U...
Published in: | Annales Geophysicae |
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Copernicus Publications
2007
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00032768 2023-05-15T13:25:43+02:00 Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths Belova, E. Dalin, P. Kirkwood, S. 2007-01 electronic https://doi.org/10.5194/angeo-25-2487-2007 https://noa.gwlb.de/receive/cop_mods_00032768 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00032722/angeo-25-2487-2007.pdf https://angeo.copernicus.org/articles/25/2487/2007/angeo-25-2487-2007.pdf eng eng Copernicus Publications Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.5194/angeo-25-2487-2007 https://noa.gwlb.de/receive/cop_mods_00032768 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00032722/angeo-25-2487-2007.pdf https://angeo.copernicus.org/articles/25/2487/2007/angeo-25-2487-2007.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2007 ftnonlinearchiv https://doi.org/10.5194/angeo-25-2487-2007 2022-02-08T22:46:05Z On 5 July 2005, simultaneous observations of Polar Mesosphere Summer Echoes (PMSE) were made using the EISCAT VHF (224 MHz) and UHF (933 MHz) radars located near Tromsø, Norway and the ALWIN VHF radar (53.5 MHz) situated on Andøya, 120 km SW of the EISCAT site. During the short interval from 12:20 UT until 12:26 UT strong echoes at about 84 km altitude were detected with all three radars. The radar volume reflectivities were found to be 4×10−13 m−1, 1.5×10−14 m−1 and 1.5×10−18 m−1 for the ALWIN, EISCAT-VHF and UHF radars, respectively. We have calculated the reflectivity ratios for each pair of radars and have compared them to ratios obtained from the turbulence-theory model proposed by Hill (1978a). We have tested different values of the turbulent energy dissipation rate ε and Schmidt number Sc, which are free parameters in the model, to try to fit theoretical reflectivity ratios to the experimental ones. No single combination of the parameters ε and Sc could be found to give a good fit. Spectral widths for the EISCAT radars were estimated from the spectra computed from the autocorrelation functions obtained in the experiment. After correction for beam-width broadening, the spectral widths are about 4 m/s for the EISCAT-VHF and 1.5–2 m/s for the UHF radar. However, according to the turbulence theory, the spectral widths in m/s should be the same for both radars. We also tested an incoherent scatter (IS) model developed by Cho et al. (1998), which takes into account the presence of charged aerosols/dust at the summer mesopause. It required very different sizes of particles for the EISCAT-VHF and UHF cases, to be able to fit the experimental spectra with model spectra. This implies that the IS model cannot explain PMSE spectra, at least not for monodisperse distributions of particles. Article in Journal/Newspaper Andøya EISCAT Tromsø Niedersächsisches Online-Archiv NOA Andøya ENVELOPE(13.982,13.982,68.185,68.185) Norway Tromsø Annales Geophysicae 25 12 2487 2496 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Belova, E. Dalin, P. Kirkwood, S. Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
topic_facet |
article Verlagsveröffentlichung |
description |
On 5 July 2005, simultaneous observations of Polar Mesosphere Summer Echoes (PMSE) were made using the EISCAT VHF (224 MHz) and UHF (933 MHz) radars located near Tromsø, Norway and the ALWIN VHF radar (53.5 MHz) situated on Andøya, 120 km SW of the EISCAT site. During the short interval from 12:20 UT until 12:26 UT strong echoes at about 84 km altitude were detected with all three radars. The radar volume reflectivities were found to be 4×10−13 m−1, 1.5×10−14 m−1 and 1.5×10−18 m−1 for the ALWIN, EISCAT-VHF and UHF radars, respectively. We have calculated the reflectivity ratios for each pair of radars and have compared them to ratios obtained from the turbulence-theory model proposed by Hill (1978a). We have tested different values of the turbulent energy dissipation rate ε and Schmidt number Sc, which are free parameters in the model, to try to fit theoretical reflectivity ratios to the experimental ones. No single combination of the parameters ε and Sc could be found to give a good fit. Spectral widths for the EISCAT radars were estimated from the spectra computed from the autocorrelation functions obtained in the experiment. After correction for beam-width broadening, the spectral widths are about 4 m/s for the EISCAT-VHF and 1.5–2 m/s for the UHF radar. However, according to the turbulence theory, the spectral widths in m/s should be the same for both radars. We also tested an incoherent scatter (IS) model developed by Cho et al. (1998), which takes into account the presence of charged aerosols/dust at the summer mesopause. It required very different sizes of particles for the EISCAT-VHF and UHF cases, to be able to fit the experimental spectra with model spectra. This implies that the IS model cannot explain PMSE spectra, at least not for monodisperse distributions of particles. |
format |
Article in Journal/Newspaper |
author |
Belova, E. Dalin, P. Kirkwood, S. |
author_facet |
Belova, E. Dalin, P. Kirkwood, S. |
author_sort |
Belova, E. |
title |
Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
title_short |
Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
title_full |
Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
title_fullStr |
Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
title_full_unstemmed |
Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
title_sort |
polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths |
publisher |
Copernicus Publications |
publishDate |
2007 |
url |
https://doi.org/10.5194/angeo-25-2487-2007 https://noa.gwlb.de/receive/cop_mods_00032768 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00032722/angeo-25-2487-2007.pdf https://angeo.copernicus.org/articles/25/2487/2007/angeo-25-2487-2007.pdf |
long_lat |
ENVELOPE(13.982,13.982,68.185,68.185) |
geographic |
Andøya Norway Tromsø |
geographic_facet |
Andøya Norway Tromsø |
genre |
Andøya EISCAT Tromsø |
genre_facet |
Andøya EISCAT Tromsø |
op_relation |
Annales Geophysicae -- http://www.bibliothek.uni-regensburg.de/ezeit/?1458425 -- https://www.ann-geophys.net/ -- https://www.ann-geophys.net/volumes.html -- http://link.springer.com/journal/585 -- 1432-0576 https://doi.org/10.5194/angeo-25-2487-2007 https://noa.gwlb.de/receive/cop_mods_00032768 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00032722/angeo-25-2487-2007.pdf https://angeo.copernicus.org/articles/25/2487/2007/angeo-25-2487-2007.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/angeo-25-2487-2007 |
container_title |
Annales Geophysicae |
container_volume |
25 |
container_issue |
12 |
container_start_page |
2487 |
op_container_end_page |
2496 |
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1766387542643441664 |