Physics of auroral phenomena : proceedings of the 35th Annual seminar, Apatity, 28 Februaru – 02 March, 2012 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2012. - 187 с. : ил., табл.

О.М. Barkhatova et al. wavelength X-rays intensity. In this case the recovery efficiency is 75%. Fig. 3 shows an example of reconstructed IAI index values (gray) by feed forward neural network with input parameters: the IAI first derivative and combination MF + AE, associated with the real values of the index IAI (black). ft** Fig. 3. Example of IAI index values reconstructed by feed forward network with addition of the IAI first derivative and the pair of parameters MF + AE (black dots), the actual value of the index IAI (gray dots). Conclusions This study is devoted to establishment of connection of Solar-magnetospheric parameters with an ionospheric IAI index and estimation of their contribution to the index value. The main results are as follows: 1. Reliability of index IAI demonstrated by influence of terminator passage effect on ionospheric disturbances. 2. Confirmed the dependence of IAI values variations on geomagnetic activity (AE and the geomagnetic field horizontal component values) and the current solar activity (long-wave X-ray radiation in the range of 1-8 A). The total contribution of Solar-magnetospheric activity is about 40%. 3. A neural network method for reconstruction of IAI index values taking into account the level of heliogeophysical activity was developed. The preferred type of neural network is a feed forward with the following input parameters: the IAI first derivative and the combination of pair of parameters: the geomagnetic field horizontal component plus index AE or geomagnetic field horizontal component plus long wavelength X-rays intensity. In this case the recovery efficiency is 75%. Thus the previously introduced index IAI is useful for the assessment of ionospheric disturbances and can be used to study the effects of Solar and geomagnetic activity on ionospheric processes. Acknowledgements. This work was supported by RFBR grants 12-05-00425, 12-02-31043 and grant "Development of advanced methods for predicting the magnetosphere-ionospheric state in order to ensure successful communication by finding the fundamental laws of Solar activity effects" executed in university in the frame of Ministry of Education and Science government order. References Balan, N., Bailey G.J., Jayachandran B. Ionospheric evidence for a nonlinear relationship between the solar e. u. v. and 10.7 cm fluxes during an intense solar cycle // Planet. Space Sci., 41, 141-145, 1993. Barkhatov N.A., Barkhatova O.M. Revealing of ionospheric disturbances classes on f2 critical frequencies long-term data. Geomagnetism and Aeronomy, 2012, V. 52, P. 510-518. Barkhatova O.M., Levitin A.E., Dodonova I.A., Kosolapova N.V. Classification of ionospheric disturbances at mid-latitudes on long-term observations. Proc. of 34th Annual Seminar "Physics of auroral phenomena", Apatity, 1-4 March 2011 PGI KSC RAS, P. 125-128. Barkhatova O.M., Smirnova A.S., Ulybina R.I. The account of Solar-magnetosphere connections in the problem of the prognosis of subauroral ionosphere parameters // Radiophysics and Quantum Electronics. 2009. V.52, N.2. P. 109-117. LSstovicka, Yue X., Wan W. Long-term trends in foF2: their estimating and origin // Ann. Geophysicae. V. 26 X» 3 P 593-598 2008. Liu J.Y., Chen Y.I., Lin J.S. Statistical investigation of the saturation effect in the ionospheric foF2 versus sunspot, solar radio noise, and solar EUV radiation// Journal of Geophysical Research, V. 108, N. A2, 1067, doi: 10.1029/2001JA007543 2003. Liu L., Wan W., Yue X., Zhao B., Ning B., Zhang M.-L. The dependence of plasma density in the topside ionosphere on the solar activity level // Ann. Geophysicae. V. 25. № 6. P. 1337-1343. 2007. Zubova Yu.V., A.A. Namgaladze Investigation of the ionospheric F-layer response to the FAC2 variations during April 16 and 17, 2002 using the Upper Atmosphere Model // Physics of Auroral Phenomena, Proc. XXXIII Annual Apatity Seminar P.159-160, 2011. 106