ROLE OF MAGNETIC RECONNECTION IN VENUS IONOPAUSE ACTIVITY

The role of magnetic reconnection in the dynamics of the Venus dayside ionopause is investigated. The dispersion relation of the resistive t earing mode for the asymmetric ionopause equilibrium is derived and so lved. It is shown that typical signatures of this mode correspond to h elical magnetic flux tubes (flux ropes) as observed by Pioneer Venus O rbiter. Nonlinear numerical MHD-simulations were carried out in additi on to the analytical investigations. The results of these simulations support our view that magnetic reconnection plays an essential role in the dynamic interaction of the solar wind with the Venus ionosphere.