A Simulation Study of the Effect of Geomagnetic Activity on the Global Circulation in the Earth’s Middle Atmosphere

Abstract

T o investigate how geomagnetic activity affects the formation of the large-scale global circulation of the middle at mosphere, t he non-hydrostatic model of the global wind system of the Earth’s atmosphere, developed earlier in the Po lar Geophysical Institute, is utilized. The model produces three-dimensional global distributions of the zonal, meridional, and vertical components of the wind velocity and neutral gas density in the troposphere, stratosphere, mesosphere, and lower thermosphere. Simulations are performed for the winter period in the northern hemisphere (16 January) and for two distinct values of geomagnetic activity (Kp = 1 and Kp = 4) . The simulation results indicate that geomagnetic activ ity ought to influence considerably on the formation of global wind system in the stratosphere, mesosphere, and lower thermosphere. The influence on the middle atmosphere is conditioned by the vertical transport of air from the lower thermosphere to the mesosphere and stratosphere and vice versa. This transport may be rather distinct under different geomagnetic activity conditions.