The estimation of D-region electron densities from riometer data
At high latitude the hard electron precipitation associated with auroral activity is a major source of ionization for the D-region, one consequence being the absorption of radio waves. Direct measurements of the D-region electron density are not readily available, however. This paper investi...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2003-02-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/21/603/2003/angeo-21-603-2003.pdf |
| _version_ | 1811308344523096064 |
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| author | J. K. Hargreaves M. Friedrich |
| author_facet | J. K. Hargreaves M. Friedrich |
| author_sort | J. K. Hargreaves |
| collection | DOAJ |
| description | At high latitude the hard
electron precipitation associated with auroral activity is a major source of
ionization for the D-region, one consequence being the absorption of radio
waves. Direct measurements of the D-region electron density are not readily
available, however. This paper investigates the relationship between the
electron density at altitudes between 100 and 70 km and the total radio
absorption observed with a riometer, with a view to using the latter to predict
the former. Tables are given of the median electron density corresponding to 1
dB absorption at 27.6 MHz for each hour of the day, and it is shown that at
certain heights the estimates will be accurate to within a factor of 1.6 on 50%
of the occasions. A systematic variation with time of day is probably
associated with a progressive hardening of the typical electron spectrum during
the morning hours. There is also evidence for a seasonal effect possibly due to
seasonal variations of the mesosphere.<br><br><b>Key words. </b>Ionosphere (auroral
ionosphere) – Radio science (ionospheric propagation; instruments and
techniques) |
| first_indexed | 2024-04-13T09:21:33Z |
| format | Article |
| id | doaj.art-d5cce946006d4134a07a81a5e1def90a |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-13T09:21:33Z |
| publishDate | 2003-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-d5cce946006d4134a07a81a5e1def90a2022-12-22T02:52:36ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762003-02-012160361310.5194/angeo-21-603-2003The estimation of D-region electron densities from riometer dataJ. K. Hargreaves0M. Friedrich1Department of Communication Systems, University of Lancaster, Lancaster, UKDepartment of Communications and Wave Propagation, Technical University of Graz, Graz, AustriaAt high latitude the hard electron precipitation associated with auroral activity is a major source of ionization for the D-region, one consequence being the absorption of radio waves. Direct measurements of the D-region electron density are not readily available, however. This paper investigates the relationship between the electron density at altitudes between 100 and 70 km and the total radio absorption observed with a riometer, with a view to using the latter to predict the former. Tables are given of the median electron density corresponding to 1 dB absorption at 27.6 MHz for each hour of the day, and it is shown that at certain heights the estimates will be accurate to within a factor of 1.6 on 50% of the occasions. A systematic variation with time of day is probably associated with a progressive hardening of the typical electron spectrum during the morning hours. There is also evidence for a seasonal effect possibly due to seasonal variations of the mesosphere.<br><br><b>Key words. </b>Ionosphere (auroral ionosphere) – Radio science (ionospheric propagation; instruments and techniques)https://www.ann-geophys.net/21/603/2003/angeo-21-603-2003.pdf |
| spellingShingle | J. K. Hargreaves M. Friedrich The estimation of D-region electron densities from riometer data Annales Geophysicae |
| title | The estimation of D-region electron densities from riometer data |
| title_full | The estimation of D-region electron densities from riometer data |
| title_fullStr | The estimation of D-region electron densities from riometer data |
| title_full_unstemmed | The estimation of D-region electron densities from riometer data |
| title_short | The estimation of D-region electron densities from riometer data |
| title_sort | estimation of d region electron densities from riometer data |
| url | https://www.ann-geophys.net/21/603/2003/angeo-21-603-2003.pdf |
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