Geomagnetic control of polar mesosphere summer echoes
Abstract. Using observations with the ALOMAR SOUSY radar near Andenes (69.3°N, 16.0°E) from 1994 until 1997 polar mesosphere summer echoes (PMSE) have been investigated in dependence on geomagnetic K indices derived at the Auroral Observa-tory Tromsø (69.66°N, 18.94°E). During night-time and morning...
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| Format: | Text |
| Language: | English |
| Published: |
2000
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.580.6001 http://www.ann-geophys.net/18/202/2000/angeo-18-202-2000.pdf |
| Summary: | Abstract. Using observations with the ALOMAR SOUSY radar near Andenes (69.3°N, 16.0°E) from 1994 until 1997 polar mesosphere summer echoes (PMSE) have been investigated in dependence on geomagnetic K indices derived at the Auroral Observa-tory Tromsø (69.66°N, 18.94°E). During night-time and morning hours a significant correlation between the signal-to-noise ratio (SNR) of the radar results and the geomagnetic K indices could be detected with a maxi-mum correlation near midnight. The correlation be-comes markedly smaller in the afternoon and early evening hours with a minimum near 17 UT. This diurnal variation is in reasonable agreement with riometer absorption at Ivalo (68.55°N, 27.28°E) and can be explained by the diurnal variation of ionization due to precipitating high energetic particles. Therefore, a part of the diurnal PMSE variation is caused by this particle precipitation. The variability of the solar EUV varia-tion, however, has no significant influence on the PMSE during the observation period. |
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