Electric potential in low latitude ionosphere: Influence of neutral wind.

Upgraded Prairie View Dynamo Code is utilized to study the dependence of electric potential in low latitude ionosphere on the intensity of neutral wind. As a matter of fact, the wind and Hall and Pedersen conductances are the main internal parameters that determine the electric potential in the ionosphere, in response to the changes in polar cap caused by interplanetary magnetic field and solar wind plasma variations, and by associated substorms in the magnetosphere. In this work, we consider the solution of the Poisson equation for electric potential, with boundary condition imposed on the division line between the open and closed field lines of IGRF- 10+T89 model field. The boundary conditions and results are dependent also on universal time, since mutual orientation of the ionospheric and the magnetospheric field is changing diurnally. The electric potential on the boundary is set from Weimer's empirical model. We present results of calculations of electric potential, for strong and moderate storms, as well as for quiet times. For better accuracy it is more important to set correctly neutral wind in quiet times, while in disturbed and stormy ones the result becomes sensitive only to boundary conditions and the ionospheric conductances distributions used in the calculation.