Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

Yu. V. Zubova, A.A. Namgaladze UT, hours Figure 2. The time variations of hmF2 (above) and foF2 (below) observed by the Sondrestrom ionosonde during April 15-20, 2002 (dots) in comparison with the UAM results (solid and dotted lines). The results presented in Figure 1 and Figure 2 confirmed our previous conclusions. The figures demonstrate the acceptable agreement of the model hmF2 values with the Millstone Hill and Sondrestrom ionosondes data especially in the UAM version using the NRLMSIS. But the numerically calculated foF2 differ values dramatically from the Millstone Hill data for the night hours of April 16 and 17, 2002. This disagreement of the foF2 values calculated by both UAM versions and the observations reaches the factor of 4 and more. So, the ionospheric plasma behaviour during night hours over Millstone Hill was caused not by the thermospheric wind variations but by the plasma convergence to the midnight meridian due to the zonal electromagnetic drift. References Namgaladze A .A , Martynenko O .V , Volkov M .A , Namgaladze A .N , Yurik R.Yu. High-latitude version o f the global numerical model of the Earth’s upper atmosphere. Proceedings o f the MSTU, v .l, No.2, p.23-84, 1998. Namgaladze A .A , Namgaladze A .N , Martynenko O .V , Doronina E .N , Knyazeva M .A , Zubova Yu.V. Numerical modeling of the thermosphere, ionosphere and plasmasphere behaviour during the April 2002 magnetic storms. Physics o fAuroral Phenomena, Proceedings o f the XXVI Annual Apatity Seminar, Preprint PGI, p.74-78, 2003. Namgaladze A .A , Zubova Yu.V , Namgaladze A .N , Martynenko O .V , Doronina E .N , Goncharenko L .P , Van Eyken A , Howells V , Thayer J.P , Taran V .I, Shpynev B , Zhou Q. Modelling of the ionosphere / thermosphere behaviour during the April 2002 magnetic storms: A comparison of the UAM results with the ISR and NRLMSISE-00 data. Adv. in Space Research, V. 37, Is. 2, 380-391,2006. Picone J.M , Hedin A .E , Drob D .P , Aikin A.C. NRLMSISE-00 empirical model o f the atmosphere: Statistical comparisons and scientific issues. J. Geophys. Res., v.107, 1468, 10.1029/2002JA009430, 2002. Zubova Yu.V , Namgaladze A .A , Goncharenko L.P. Model interpretation o f the unusual F-region night-time electron density behaviour observed by the Millstone Hill incoherent scatter radar on April 16-17, 2002. Proceedings o f the 7th International Conference "Problems o f Geocosmos", Saint-Petersburg, p.304-308, 2008. 1 6 0