Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation
Non-thermal echoes in incoherent scatter radar observations are occasionally seen in the high-latitude ionosphere. Such anomalous echoes are a manifestation of plasma instabilities on spatial scales matching the radar wavelength. Here we investigate the occurrence of a class of spatially localiz...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-03-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/35/475/2017/angeo-35-475-2017.pdf |
| _version_ | 1828295115609735168 |
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| author | H. Dahlgren H. Dahlgren N. M. Schlatter N. Ivchenko L. Roth A. Karlsson |
| author_facet | H. Dahlgren H. Dahlgren N. M. Schlatter N. Ivchenko L. Roth A. Karlsson |
| author_sort | H. Dahlgren |
| collection | DOAJ |
| description | Non-thermal echoes in
incoherent scatter radar observations are occasionally seen in the
high-latitude ionosphere. Such anomalous echoes are a manifestation of plasma
instabilities on spatial scales matching the radar wavelength. Here we
investigate the occurrence of a class of spatially localized anomalous echoes
with an enhanced zero Doppler frequency feature and their relation to auroral
particle precipitation. The ionization profile of the E region is used to
parametrize the precipitation, with nmE and hmE being the E region peak
electron density and the altitude of the peak, respectively. We find the
occurrence rate of the echoes to generally increase with nmE and decrease
with hmE, thereby indicating a correlation between the echoes and high-energy
flux precipitation of particles with a high characteristic energy. The
highest occurrence rate of > 20 % is found for hmE = 109 km and
nmE = 10<sup>11. 9</sup> m<sup>−3</sup>, averaged over the radar observation volume. |
| first_indexed | 2024-04-13T11:48:17Z |
| format | Article |
| id | doaj.art-5a0e29f65bc5474da01acb7e3934b19f |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-13T11:48:17Z |
| publishDate | 2017-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-5a0e29f65bc5474da01acb7e3934b19f2022-12-22T02:48:07ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762017-03-013547547910.5194/angeo-35-475-2017Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitationH. Dahlgren0H. Dahlgren1N. M. Schlatter2N. Ivchenko3L. Roth4A. Karlsson5School of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, SwedenSchool of Physics and Astronomy, University of Southampton, Southampton, UKSchool of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, SwedenSchool of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, SwedenSchool of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, SwedenSchool of Electrical Engineering, Royal Institute of Technology KTH, Stockholm, SwedenNon-thermal echoes in incoherent scatter radar observations are occasionally seen in the high-latitude ionosphere. Such anomalous echoes are a manifestation of plasma instabilities on spatial scales matching the radar wavelength. Here we investigate the occurrence of a class of spatially localized anomalous echoes with an enhanced zero Doppler frequency feature and their relation to auroral particle precipitation. The ionization profile of the E region is used to parametrize the precipitation, with nmE and hmE being the E region peak electron density and the altitude of the peak, respectively. We find the occurrence rate of the echoes to generally increase with nmE and decrease with hmE, thereby indicating a correlation between the echoes and high-energy flux precipitation of particles with a high characteristic energy. The highest occurrence rate of > 20 % is found for hmE = 109 km and nmE = 10<sup>11. 9</sup> m<sup>−3</sup>, averaged over the radar observation volume.https://www.ann-geophys.net/35/475/2017/angeo-35-475-2017.pdf |
| spellingShingle | H. Dahlgren H. Dahlgren N. M. Schlatter N. Ivchenko L. Roth A. Karlsson Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation Annales Geophysicae |
| title | Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation |
| title_full | Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation |
| title_fullStr | Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation |
| title_full_unstemmed | Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation |
| title_short | Relation of anomalous F region radar echoes in the high-latitude ionosphere to auroral precipitation |
| title_sort | relation of anomalous f region radar echoes in the high latitude ionosphere to auroral precipitation |
| url | https://www.ann-geophys.net/35/475/2017/angeo-35-475-2017.pdf |
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