Ionospheric processes during the 7–10 November 2004 extreme geospace storm. 1. Observation results
|1Grigorenko, Ye.I, 1Emelyanov, LYa., 1Pazura, SA, 2Chernogor, LF |
1Institute of Ionosphere of the National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, Kharkiv, Ukraine
2V.N. Karazin National University of Kharkiv, Kharkiv, Ukraine
|Kosm. nauka tehnol. 2007, 13 ;(4):062-076|
|Publication Language: Russian|
The study results of the F2 region and topside ionosphere behaviour during the 7–10 November 2004 geospace storm that arises from the imposition of two consistent extreme magnetic disturbances (Крmax= 8.7) are presented. The observations were carried out with the Kharkiv incoherent scatter radar. Substantial effects of negative ionosphere disturbance were detected. Among them were the decrease in the F2 layer peak electron density by a factor of 6–7 and in the total electron content below 1000 km height by a factor of 2, uplifting in the ionosphere F2 layer height by about 300 km during the night and by 150–180 km in the daytime, unusual night heating of plasma with increase of ion and electron temperatures by up to 2000 and 3000 K, respectively; decrease of the fractional hydrogen ion density N (H +)/Ne by a factor of 3.5 due to the emptying of the magnetic flux tube over Kharkiv. During the main storm phase the effects that are usually peculiar to the high latitude ionosphere including coherent echoes were revealed. The results obtained can point to the shift of large-scale structures of the high latitude ionosphere (auroral oval, main ionospheric trough, hot zone etc.) to the latitudes that are closed to the Kharkiv radar latitude.
|Keywords: electron density, ionosphere disturbance, radar|
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