Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons
Energetic electrons (tens to hundreds of keV) deposit significant energy into the D layer of the ionosphere. Riometers provide a means of monitoring this electron precipitation by measuring the associated cosmic noise absorption (CNA), but individually they are incapable of resolving the associated...
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ftulancaster:oai:eprints.lancs.ac.uk:34964 2023-08-27T04:09:13+02:00 Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons Wild, P. Honary, F. Kavanagh, A.J. Senior, A. 2010-12-21 application/pdf https://eprints.lancs.ac.uk/id/eprint/34964/ https://eprints.lancs.ac.uk/id/eprint/34964/1/art_1017.pdf https://doi.org/10.1029/2010JA015766 en eng https://eprints.lancs.ac.uk/id/eprint/34964/1/art_1017.pdf Wild, P. and Honary, F. and Kavanagh, A.J. and Senior, A. (2010) Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons. Journal of Geophysical Research, 115 (A12326). pp. 1-11. ISSN 0148-0227 Journal Article PeerReviewed 2010 ftulancaster https://doi.org/10.1029/2010JA015766 2023-08-03T22:20:03Z Energetic electrons (tens to hundreds of keV) deposit significant energy into the D layer of the ionosphere. Riometers provide a means of monitoring this electron precipitation by measuring the associated cosmic noise absorption (CNA), but individually they are incapable of resolving the associated energy. However, the combination of two imaging riometers with overlapping beams allows an estimate of the height of peak CNA and so the associated energy to be made. We examine two methods for estimating the height of CNA using data from two imaging riometers in northern Fennoscandia; a 3-D reconstruction of CNA using Occam's inversion and a technique based upon the triangulation of discrete absorption structures are developed. We compare these two methods with the results from a previously published technique. It is found that for the case studies and test phantoms the height triangulation and 3-D reconstruction offer improvement over previous methods. These techniques are tested by comparison with data from the EISCAT incoherent scatter radar. Observations show good correlation between the estimates of peak height of CNA from EISCAT and from the triangulation and 3-D reconstruction methods for this case. Three case studies are examined in detail, a slowly varying absorption, afternoon spike, and evening absorption spike event. Estimates of the characteristic energy are made. The substorm event had a characteristic energy of ∼5 keV, whereas the characteristic energy for the morning event was 17–20 keV. Analyses indicate the afternoon spike event having characteristic energy greater than 100 keV. Article in Journal/Newspaper EISCAT Fennoscandia Lancaster University: Lancaster Eprints Journal of Geophysical Research: Space Physics 115 A12 n/a n/a |
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Lancaster University: Lancaster Eprints |
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ftulancaster |
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English |
description |
Energetic electrons (tens to hundreds of keV) deposit significant energy into the D layer of the ionosphere. Riometers provide a means of monitoring this electron precipitation by measuring the associated cosmic noise absorption (CNA), but individually they are incapable of resolving the associated energy. However, the combination of two imaging riometers with overlapping beams allows an estimate of the height of peak CNA and so the associated energy to be made. We examine two methods for estimating the height of CNA using data from two imaging riometers in northern Fennoscandia; a 3-D reconstruction of CNA using Occam's inversion and a technique based upon the triangulation of discrete absorption structures are developed. We compare these two methods with the results from a previously published technique. It is found that for the case studies and test phantoms the height triangulation and 3-D reconstruction offer improvement over previous methods. These techniques are tested by comparison with data from the EISCAT incoherent scatter radar. Observations show good correlation between the estimates of peak height of CNA from EISCAT and from the triangulation and 3-D reconstruction methods for this case. Three case studies are examined in detail, a slowly varying absorption, afternoon spike, and evening absorption spike event. Estimates of the characteristic energy are made. The substorm event had a characteristic energy of ∼5 keV, whereas the characteristic energy for the morning event was 17–20 keV. Analyses indicate the afternoon spike event having characteristic energy greater than 100 keV. |
format |
Article in Journal/Newspaper |
author |
Wild, P. Honary, F. Kavanagh, A.J. Senior, A. |
spellingShingle |
Wild, P. Honary, F. Kavanagh, A.J. Senior, A. Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons |
author_facet |
Wild, P. Honary, F. Kavanagh, A.J. Senior, A. |
author_sort |
Wild, P. |
title |
Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons |
title_short |
Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons |
title_full |
Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons |
title_fullStr |
Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons |
title_full_unstemmed |
Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons |
title_sort |
triangulating the height of cosmic noise absorption: a method for estimating the characteristic energy of precipitating electrons |
publishDate |
2010 |
url |
https://eprints.lancs.ac.uk/id/eprint/34964/ https://eprints.lancs.ac.uk/id/eprint/34964/1/art_1017.pdf https://doi.org/10.1029/2010JA015766 |
genre |
EISCAT Fennoscandia |
genre_facet |
EISCAT Fennoscandia |
op_relation |
https://eprints.lancs.ac.uk/id/eprint/34964/1/art_1017.pdf Wild, P. and Honary, F. and Kavanagh, A.J. and Senior, A. (2010) Triangulating the height of cosmic noise absorption: A method for estimating the characteristic energy of precipitating electrons. Journal of Geophysical Research, 115 (A12326). pp. 1-11. ISSN 0148-0227 |
op_doi |
https://doi.org/10.1029/2010JA015766 |
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Journal of Geophysical Research: Space Physics |
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115 |
container_issue |
A12 |
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1775350384295936000 |