Infrasound - The cause of strong Polar Mesosphere Winter Echoes?
The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from the mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event in November 2004. Using the interferometric capabilities of ESRAD it was found that th...
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ftleibnizopen:oai:oai.leibnizopen.de:hiaOVYsBBwLIz6xGu-wF 2023-11-12T04:16:36+01:00 Infrasound - The cause of strong Polar Mesosphere Winter Echoes? Kirkwood, S. Chilson, P. Belova, E. Dalin, P. Häggström, I. Rietveld, M. Singer, W. 2006 application/pdf https://doi.org/10.34657/1566 https://oa.tib.eu/renate/handle/123456789/4055 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Annales Geophysicae, Volume 24, Issue 2, Page 475-491 acoustic wave echo sounding mesosphere radar 530 article Text 2006 ftleibnizopen https://doi.org/10.34657/1566 2023-10-22T23:17:19Z The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from the mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event in November 2004. Using the interferometric capabilities of ESRAD it was found that the scatterers responsible for PMWE show very high horizontal travel speeds, up to 500 ms-1 or more, and high aspect sensitivity, with echo arrival angles spread over as little as 0.3°. ESRAD also detected, on some occasions, discrete scattering regions moving across the field of view with periodicities of a few seconds. The very narrow, vertically directed beam of the more powerful EISCAT radar allowed measurements of the spectral widths of the radar echoes both inside the PMWE and from the background plasma above and below the PMWE. Spectral widths inside the PMWE were found to be indistinguishable from those from the background plasma. We propose that scatter from highly-damped ion-acoustic waves generated by partial reflection of infrasonic waves provides a reasonable explanation of the characteristics of the very strong PMWE reported here. publishedVersion Article in Journal/Newspaper EISCAT Unknown |
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language |
English |
topic |
acoustic wave echo sounding mesosphere radar 530 |
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acoustic wave echo sounding mesosphere radar 530 Kirkwood, S. Chilson, P. Belova, E. Dalin, P. Häggström, I. Rietveld, M. Singer, W. Infrasound - The cause of strong Polar Mesosphere Winter Echoes? |
topic_facet |
acoustic wave echo sounding mesosphere radar 530 |
description |
The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from the mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event in November 2004. Using the interferometric capabilities of ESRAD it was found that the scatterers responsible for PMWE show very high horizontal travel speeds, up to 500 ms-1 or more, and high aspect sensitivity, with echo arrival angles spread over as little as 0.3°. ESRAD also detected, on some occasions, discrete scattering regions moving across the field of view with periodicities of a few seconds. The very narrow, vertically directed beam of the more powerful EISCAT radar allowed measurements of the spectral widths of the radar echoes both inside the PMWE and from the background plasma above and below the PMWE. Spectral widths inside the PMWE were found to be indistinguishable from those from the background plasma. We propose that scatter from highly-damped ion-acoustic waves generated by partial reflection of infrasonic waves provides a reasonable explanation of the characteristics of the very strong PMWE reported here. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Kirkwood, S. Chilson, P. Belova, E. Dalin, P. Häggström, I. Rietveld, M. Singer, W. |
author_facet |
Kirkwood, S. Chilson, P. Belova, E. Dalin, P. Häggström, I. Rietveld, M. Singer, W. |
author_sort |
Kirkwood, S. |
title |
Infrasound - The cause of strong Polar Mesosphere Winter Echoes? |
title_short |
Infrasound - The cause of strong Polar Mesosphere Winter Echoes? |
title_full |
Infrasound - The cause of strong Polar Mesosphere Winter Echoes? |
title_fullStr |
Infrasound - The cause of strong Polar Mesosphere Winter Echoes? |
title_full_unstemmed |
Infrasound - The cause of strong Polar Mesosphere Winter Echoes? |
title_sort |
infrasound - the cause of strong polar mesosphere winter echoes? |
publisher |
München : European Geopyhsical Union |
publishDate |
2006 |
url |
https://doi.org/10.34657/1566 https://oa.tib.eu/renate/handle/123456789/4055 |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Volume 24, Issue 2, Page 475-491 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/1566 |
_version_ |
1782333653636874240 |