Physics of auroral phenomena : proceedings of the 36th Annual seminar, Apatity, 26 February – 01 March, 2013 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2013. - 215 с. : ил., табл.

I. V. Mingalev et al. From the obtained results for winter period in the northern hemisphere, we can see that at levels of the stratosphere and mesosphere, the motion of the neutral gas in the northern hemisphere is primarily eastward, so a circumpolar cyclone is formed. It can be noticed that the center of the northern cyclone may be displaced from the pole. Simultaneously, the motion of the neutral gas is primarily westward in the southern hemisphere at levels of the stratosphere and mesosphere, so a circumpolar anticyclone is formed for summer period of the southern hemisphere. Let us consider simulation results, obtained for distinct values of magnetic activity, and their distinctions. From the obtained results, one can see that the horizontal wind velocity in the circumpolar cyclone o f the northern hemisphere, obtained for low magnetic activity, is less than that, obtained for considerable magnetic activity. Similarly, the horizontal wind velocity in the circumpolar anticyclone of the southern hemisphere, obtained for low magnetic activity, is less than that, obtained for considerable magnetic activity. From the obtained results, we can see that, for winter period in the northern hemisphere, at levels of the mesosphere, the vertical wind velocity can have opposite directions in the horizontal domains having different configurations. Maximal absolute values of the downward vertical wind component are commensurable with the maximal module of the upward vertical wind component for conditions of low magnetic activity. On the contrary, for conditions of considerable magnetic activity, maximal absolute values o f the downward and upward vertical wind components can be rather different. Simulation results, obtained for January conditions, indicate that, despite o f independence of the atmospheric temperature on the magnetic activity below approximately 80 km, the influence o f the magnetic activity level on the global circulation of the stratosphere and mesosphere does exist. This influence is a consequence of a relationship between large-scale circulations of the middle atmosphere and thermosphere, with the thermospheric circulation being dependent on the magnetic activity level, undoubtedly. The influence is conditioned by the vertical transport of air from the lower thermosphere to the mesosphere and stratosphere. This transport may be rather different under distinct magnetic activity conditions. Conclusion The non-hydrostatic model of the global neutral wind system of the Earth’s atmosphere, developed earlier in the Polar Geophysical Institute, was utilized to investigate how magnetic activity affects the formation o f the large-scale global circulation of the stratosphere, mesosphere, and lower thermosphere for January conditions. The simulation results indicate that magnetic activity ought to influence considerably on the formation of global neutral wind system in the stratosphere, mesosphere, and lower thermosphere. However, this influence is not straightforward. Undoubtedly, at levels of the lower thermosphere, this influence is conditioned by the differences of the temperature distributions, obtained for various values of geomagnetic activity at these levels. However, from the simulation results obtained, we can see that the atmospheric temperature, calculated with the help of the NRLMSISE-00 empirical model, does not depend on the geomagnetic activity below approximately 80 km. Nevertheless, the effect of geomagnetic activity on the global circulation o f the atmosphere below 80 km exists. This effect is conditioned by the vertical transport of air from the lower thermosphere to the mesosphere, stratosphere, and upper troposphere, eventually, and vice versa. The simulation results indicate that this vertical transport may be rather distinct under different geomagnetic activity conditions. It can be noticed that the utilized mathematical model was able to simulate this effect due to the fact that the model is non-hydrostatic. A cknow ledgm ents. This work was partly supported by the RFBR grant 13-01-00063. References Mingalev, I.V. and V.S. Mingalev, The global circulation model of the lower and middle atmosphere of the Earth with a given temperature distribution, Mathematical Modeling, 17(5), 24-40, 2005 (in Russian). Mingalev, I.V., V.S. Mingalev, and G.I. Mingaleva, Numerical simulation o f global distributions o f the horizontal and vertical wind in the middle atmosphere using a given neutral gas temperature field, J. Atmos Sol -Terr Phys 69,552-568,2007. Mingalev, I.V., V.S. Mingalev, and G.I. Mingaleva, Numerical simulation o f the global neutral wind system of the Earth’s middle atmosphere for different seasons. Atmosphere, 3, 213-228, 2012. Mingalev I., Mingalev V. Numerical modeling of the influence of solar activity on the global circulation in the Earth’s mesosphere and lower thermosphere // International Journal o f Geophysics, Volume 2012 Article ID 106035,15 pages, doi: 10.1155/2012/106035. Picone, J.M., A.E.Hedin, D.P. Drob, and A.C. Aikin, NRLMSISE-00 empirical model o f the atmosphere: Statistical comparisons and scientific issues, J. Geophys. Res., 107A, (SIA 15) 1-16, 2002. 158