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.

“P hysics o f Auroral P henom ena", Proc. XXXIII A n n u a l Sem inar, Apatity, pp. 79 - 82, 2011 © Kola Science Centre, Russian Academy of Science, 2011 Polar Geophysical Institute EFFECTS OF THE LONG -TERM VARIATIONS OF THE SOLAR WIND ON THE NEAR-EARTH SPACE L. N. Makarova, A.V. Shirochkov, and A .V . F ra n k -K am e n e ts k y (Arctic and Antarctic Research Institute, 38, Bering Street 199397 Saint-Petersburg, Russian Federation) Abstract. There are a lot of the data o f the solar wind parameters accumulated during epoch of the satellite exploration o f the Space. It is possible to study interconnection between the long - term variations of the parameters of the solar wind and of the near - Earth Space during the last 4 cycles of the solar activity. We analyze quasi - stationary variations of the solar wind parameters during the solar cycle 23 in comparison with the correspondent changes in the cycles 20, 21 and 22. It was found that the main peculiarities of the cycle 23 are unusually low values of the solar wind magnetic field. We suggest that such long - term variations o f the solar activity could change geoefficiency of the solar wind parameters which is expressed as diminishing of the electromagnetic energy transferred into the near - Earth Space. Therefore the global electric circuit parameters are changing correspondingly producing significant variations in the Earth ionosphere and atmosphere and indirectly in the planet climate. The latest experimentally observed low values of the ground surface electric field, low concentration of the charged particles in the ionosphere, increasing area of the ice cover in the Arctic could be attributed to these changes in the solarwind parameters. 1. Introduction The Sun rotates around its axis but its various zones and layers turn with different velocities. The resulting shear due to difference in speed between adjacent regions twists and intensifies magnetic fields. Giant loops of hot plasma contained by the magnetic fields lift off the Sun's surface. The Sun produces a constant stream of particles which billow out into the space. In fact, 1 million tons of particles come from the Sun every second. This stream of particles is called the solar wind. A non-stop solar wind consisting o f electrons and charged atoms travels past the Earth and far beyond the outermost planets. Near the Earth the plasma density is only about 6 particles per cubic centimeter, compared to 2.5 x 10 19 molecules /cm 3 in the Earth’s sea level atmosphere. Nevertheless, it is responsible for such specific phenomena as: forming structure o f magnetosphere, dynamic processes and structure of electric fields inside magnetosphere. It is possible to speak about a specific kind of the solar activity influence on the Earth - the energy of the solar wind connected with vast areas of the Sun surface but stipulated by the solar magnetic fields. This kind of the solar activity can determine long -term variations of some parameters of the near- Earth space. The aim o f this paper is to try to show direct connection between the solar wind magnitude field and the parameters o f the high latitude ionosphere. 2. Experimental data In this paper we used data of the solar activity and the parameters of the solar wind accumulated in the epoch of satellite explorations. As a level of the solar activity the number of Sun spots (W) was used. Results of analysis of the long - term variations of full vector of the magnetic field of the solar wind will be presented here. Period of observation is 42 years (from 1965 till 2010). The data were taken from INTERNET OMNI system. The hourly values of different parameters of the solar wind were used as original material. Afterwards the averaged monthly and annual values were calculated from it. The long - term variations (1965 - 2007 years) of such parameters of the solar wind as its density and velocity, three components and full vector of interplanetary magnetic field (IMF) were studied. In this paper we used data of the hourly values of ionospheric parameters of the station Sodankyla, Finland (Ф' = 64.0°) from 1965 till 2007 years. Results of comparison of the solar activity and the values of the IMF full vector with parameters of the ionosphere are presented below. 3. Results of experimental data analysis Existence of long term experimental data o f ionosphere were using for study of connection f 0 F2 и hmaxF2 with solar activity expressed by Sun spot number and full vector of the magnetic field of the solar wind which is connected with large magnetic fields of the Sun. Mean annual values of number of Sun spot (W), full vector of IMF (Bsw), critical frequency (hroaxF2) and of altitude of maximum of F2 layer (hmaxF2) are presented on Figure 1. Similarity o f long -term variations of the Sun spot number and the f 0 F2 shows that EUV radiation is the main source o f energy o f ionization of atmosphere. The value of the coefficient correlation between these two parameters is very high and equal 0.95 with high level of statistical confidence. Asymmetry of cyclic solar activity is clearer in variations o f the values o f full vector IMF, rather than in W dynamics. 79