The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations
On 30 October 2004 during a strong solar proton event, layers of enhanced backscatter from altitudes between 55 and 75km have been observed by both ESRAD (52MHz) and the EISCAT VHF (224MHz) radars. These echoes have earlier been termed Polar Mesosphere Winter Echoes, PMWE. After considering the morp...
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ftdoajarticles:oai:doaj.org/article:ddaf7bdbfd0048d0bbe279cfb3cc762e 2023-05-15T16:04:29+02:00 The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations E. Belova S. Kirkwood J. Ekeberg A. Osepian I. Häggström H. Nilsson M. Rietveld 2005-06-01T00:00:00Z https://doi.org/10.5194/angeo-23-1239-2005 https://doaj.org/article/ddaf7bdbfd0048d0bbe279cfb3cc762e EN eng Copernicus Publications https://www.ann-geophys.net/23/1239/2005/angeo-23-1239-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-1239-2005 0992-7689 1432-0576 https://doaj.org/article/ddaf7bdbfd0048d0bbe279cfb3cc762e Annales Geophysicae, Vol 23, Pp 1239-1247 (2005) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article 2005 ftdoajarticles https://doi.org/10.5194/angeo-23-1239-2005 2022-12-31T03:16:04Z On 30 October 2004 during a strong solar proton event, layers of enhanced backscatter from altitudes between 55 and 75km have been observed by both ESRAD (52MHz) and the EISCAT VHF (224MHz) radars. These echoes have earlier been termed Polar Mesosphere Winter Echoes, PMWE. After considering the morphology of the layers and their relation to observed atmospheric waves, we conclude that the radars have likely seen the same phenomenon even though the radars' scattering volumes are located about 220km apart and that the most long-lasting layer is likely associated with wind-shear in an inertio-gravity wave. An ion-chemistry model is used to determine parameters necessary to relate wind-shear induced turbulent energy dissipation rates to radar backscatter. The model is verified by comparison with electron density profiles measured by the EISCAT VHF radar. Observed radar signal strengths are found to be 2-3 orders of magnitude stronger than the maximum which can be expected from neutral turbulence alone, assuming that previously published results relating radar signal scatter to turbulence parameters, and turbulence parameters to wind shear, are correct. The possibility remains that some additional or alternative mechanism may be involved in producing PMWE, such as layers of charged dust/smoke particles or large cluster ions. Article in Journal/Newspaper EISCAT Directory of Open Access Journals: DOAJ Articles Annales Geophysicae 23 4 1239 1247 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 E. Belova S. Kirkwood J. Ekeberg A. Osepian I. Häggström H. Nilsson M. Rietveld The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
On 30 October 2004 during a strong solar proton event, layers of enhanced backscatter from altitudes between 55 and 75km have been observed by both ESRAD (52MHz) and the EISCAT VHF (224MHz) radars. These echoes have earlier been termed Polar Mesosphere Winter Echoes, PMWE. After considering the morphology of the layers and their relation to observed atmospheric waves, we conclude that the radars have likely seen the same phenomenon even though the radars' scattering volumes are located about 220km apart and that the most long-lasting layer is likely associated with wind-shear in an inertio-gravity wave. An ion-chemistry model is used to determine parameters necessary to relate wind-shear induced turbulent energy dissipation rates to radar backscatter. The model is verified by comparison with electron density profiles measured by the EISCAT VHF radar. Observed radar signal strengths are found to be 2-3 orders of magnitude stronger than the maximum which can be expected from neutral turbulence alone, assuming that previously published results relating radar signal scatter to turbulence parameters, and turbulence parameters to wind shear, are correct. The possibility remains that some additional or alternative mechanism may be involved in producing PMWE, such as layers of charged dust/smoke particles or large cluster ions. |
format |
Article in Journal/Newspaper |
author |
E. Belova S. Kirkwood J. Ekeberg A. Osepian I. Häggström H. Nilsson M. Rietveld |
author_facet |
E. Belova S. Kirkwood J. Ekeberg A. Osepian I. Häggström H. Nilsson M. Rietveld |
author_sort |
E. Belova |
title |
The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations |
title_short |
The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations |
title_full |
The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations |
title_fullStr |
The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations |
title_full_unstemmed |
The dynamical background of polar mesosphere winter echoes from simultaneous EISCAT and ESRAD observations |
title_sort |
dynamical background of polar mesosphere winter echoes from simultaneous eiscat and esrad observations |
publisher |
Copernicus Publications |
publishDate |
2005 |
url |
https://doi.org/10.5194/angeo-23-1239-2005 https://doaj.org/article/ddaf7bdbfd0048d0bbe279cfb3cc762e |
genre |
EISCAT |
genre_facet |
EISCAT |
op_source |
Annales Geophysicae, Vol 23, Pp 1239-1247 (2005) |
op_relation |
https://www.ann-geophys.net/23/1239/2005/angeo-23-1239-2005.pdf https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 doi:10.5194/angeo-23-1239-2005 0992-7689 1432-0576 https://doaj.org/article/ddaf7bdbfd0048d0bbe279cfb3cc762e |
op_doi |
https://doi.org/10.5194/angeo-23-1239-2005 |
container_title |
Annales Geophysicae |
container_volume |
23 |
container_issue |
4 |
container_start_page |
1239 |
op_container_end_page |
1247 |
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1766400071475134464 |