Velocities of auroral coherent echoes at 12 and 144 MHz
Two Doppler coherent radar systems are currently working at Hankasalmi, Finland, the STARE and CUTLASS radars operating at ~144 MHz and ~12 MHz, respectively. The STARE beam 3 is nearly co-located with the CUTLASS beam 5, providing an opportunity for echo velocity comparison along the same d...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2002-10-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/20/1647/2002/angeo-20-1647-2002.pdf |
| _version_ | 1818617579080515584 |
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| author | A. V. Koustov A. V. Koustov A. V. Koustov A. V. Koustov D. W. Danskin M. V. Uspensky M. V. Uspensky T. Ogawa P. Janhunen N. Nishitani S. Nozawa M. Lester S. Milan |
| author_facet | A. V. Koustov A. V. Koustov A. V. Koustov A. V. Koustov D. W. Danskin M. V. Uspensky M. V. Uspensky T. Ogawa P. Janhunen N. Nishitani S. Nozawa M. Lester S. Milan |
| author_sort | A. V. Koustov |
| collection | DOAJ |
| description | Two Doppler coherent radar systems are
currently working at Hankasalmi, Finland, the STARE and CUTLASS radars
operating at ~144 MHz and ~12 MHz, respectively. The STARE beam 3 is nearly
co-located with the CUTLASS beam 5, providing an opportunity for echo velocity
comparison along the same direction but at significantly different radar
frequencies. In this study we consider an event when STARE radar echoes are
detected at the same ranges as CUT-LASS radar echoes. The observations are
complemented by EISCAT measurements of the ionospheric electric field and
electron density behaviour at one range of 900 km. Two separate situations are
studied; for the first one, CUTLASS observed F-region echoes (including the
range of the EIS-CAT measurements), while for the second one CUTLASS observed
E-region echoes. In both cases STARE E-region measurements were available. We
show that F-region CUT-LASS velocities agree well with the convection component
along the CUTLASS radar beam, while STARE velocities are typically smaller by a
factor of 2–3. For the second case, STARE velocities are found to be either
smaller or larger than CUTLASS velocities, depending on the range. Plasma
physics of E-and F-region irregularities is discussed in attempt to explain the
inferred relationship between various velocities. Special attention is paid to
ionospheric refraction that is important for the detection of 12-MHz
echoes.<br><br><b>Key words.</b> Ionosphere (ionospheric irregularities;
plasma waves and instabilities; auroral ionosphere) |
| first_indexed | 2024-12-16T17:07:56Z |
| format | Article |
| id | doaj.art-a32183e9076f4c2e98f082f0c54612e9 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-16T17:07:56Z |
| publishDate | 2002-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-a32183e9076f4c2e98f082f0c54612e92022-12-21T22:23:31ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762002-10-01201647166110.5194/angeo-20-1647-2002Velocities of auroral coherent echoes at 12 and 144 MHzA. V. Koustov0A. V. Koustov1A. V. Koustov2A. V. Koustov3D. W. Danskin4M. V. Uspensky5M. V. Uspensky6T. Ogawa7P. Janhunen8N. Nishitani9S. Nozawa10M. Lester11S. Milan12Solar-Terrestrial Environment Laboratory, Nagoya University, 3–13 Honohara, Toyokawa, Aichi 442, JapanInstitute of Space and Atmospheric Studies, University of Saskatchewan, 116 Science Place, Saskatoon, S7N 5E2 CanadaCorrespondence to: A. V. Koustov(koustov@dansas.usask.ca)Institute of Space and Atmospheric Studies, University of Saskatchewan, 116 Science Place, Saskatoon, S7N 5E2 CanadaMurmansk State Technical University, Sportivnaya 13, Murmansk, 183010 RussiaFinnish Meteorological Institute, Vuorikatu 15A, P.O. Box 503, Helsinki FIN-00101, FinlandSolar-Terrestrial Environment Laboratory, Nagoya University, 3–13 Honohara, Toyokawa, Aichi 442, JapanFinnish Meteorological Institute, Vuorikatu 15A, P.O. Box 503, Helsinki FIN-00101, FinlandSolar-Terrestrial Environment Laboratory, Nagoya University, 3–13 Honohara, Toyokawa, Aichi 442, JapanSolar-Terrestrial Environment Laboratory, Nagoya University, 3–13 Honohara, Toyokawa, Aichi 442, JapanDepartment of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH UKDepartment of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH UKTwo Doppler coherent radar systems are currently working at Hankasalmi, Finland, the STARE and CUTLASS radars operating at ~144 MHz and ~12 MHz, respectively. The STARE beam 3 is nearly co-located with the CUTLASS beam 5, providing an opportunity for echo velocity comparison along the same direction but at significantly different radar frequencies. In this study we consider an event when STARE radar echoes are detected at the same ranges as CUT-LASS radar echoes. The observations are complemented by EISCAT measurements of the ionospheric electric field and electron density behaviour at one range of 900 km. Two separate situations are studied; for the first one, CUTLASS observed F-region echoes (including the range of the EIS-CAT measurements), while for the second one CUTLASS observed E-region echoes. In both cases STARE E-region measurements were available. We show that F-region CUT-LASS velocities agree well with the convection component along the CUTLASS radar beam, while STARE velocities are typically smaller by a factor of 2–3. For the second case, STARE velocities are found to be either smaller or larger than CUTLASS velocities, depending on the range. Plasma physics of E-and F-region irregularities is discussed in attempt to explain the inferred relationship between various velocities. Special attention is paid to ionospheric refraction that is important for the detection of 12-MHz echoes.<br><br><b>Key words.</b> Ionosphere (ionospheric irregularities; plasma waves and instabilities; auroral ionosphere)https://www.ann-geophys.net/20/1647/2002/angeo-20-1647-2002.pdf |
| spellingShingle | A. V. Koustov A. V. Koustov A. V. Koustov A. V. Koustov D. W. Danskin M. V. Uspensky M. V. Uspensky T. Ogawa P. Janhunen N. Nishitani S. Nozawa M. Lester S. Milan Velocities of auroral coherent echoes at 12 and 144 MHz Annales Geophysicae |
| title | Velocities of auroral coherent echoes at 12 and 144 MHz |
| title_full | Velocities of auroral coherent echoes at 12 and 144 MHz |
| title_fullStr | Velocities of auroral coherent echoes at 12 and 144 MHz |
| title_full_unstemmed | Velocities of auroral coherent echoes at 12 and 144 MHz |
| title_short | Velocities of auroral coherent echoes at 12 and 144 MHz |
| title_sort | velocities of auroral coherent echoes at 12 and 144 mhz |
| url | https://www.ann-geophys.net/20/1647/2002/angeo-20-1647-2002.pdf |
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