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.

L.N. Makarova at al. Latest experimental data shows that value of the solar wind o f the magnetic field have very low values (Figure 5). Values of the solar wind of the magnetic field in period September - November 2009 year were not more 4 nTl. So, altitude of maximum of F2 layer must very low. 09/19/2009 10/13/2009 11/06/2009 11/30/2009 12/24/2009 01/17/2010 02/10/2010 10/01/2009 10/25/2009 11/18/2009 12/12/2009 01/05/2010 01/29/2010 02/22/2010 Date (mm/dd/yyyy) Figure 5 Variations o f solar wind total magnetic-field vector magnitude (B), since 09.2009 till 02.2010. Blue line is moving average with 10 days interval. Simulation and experimental research demonstrated that maximal electron density o f F2 layer decreases descending of F2 layer. But maximal electron density of F2 ionosphere layer can increases during of the low solar activity when the thermosphere is dense from processes of ionization. Obtained results in this research demonstrated it. Model IRI contains information about the ionosphere state until the year 2007. So the model is not adopted for such a low values of the solar wind parameters and consequently to low values o f maximal altitude and electron density in F2 layer. That is an explanation to such a magnificent difference between model results and the real vertical electron concentration distribution. Summary Experimental and calculated parameters of the ionograms as well as o f vertical profiles of electron density were compared for the same periods of time. The investigations of experimental and calculated parameters o f the ionograms which have been done in this paper allow us to determine that: a) IRI simulation results describe well both electron density and altitude o f ionospheric layer E. b) Comparison of IRI simulation results with real data shows than in conditions of low solar activity, observed during considered period, model gives disagreement with real values o f F2 layer parameters and have to be corrected. But it can be used for overview of ionosphere condition for different purposes which don’t need height accuracy.- References 1. http://iri.gsfc.nasa.gov/ 2. О. K. Garriott, H. Rishbet, Introduction to ionosphere physics, New York, London, 1969. 128