Evolution of IMF <i>B</i> _<i>y</i> Induced Asymmetries: The Role of Tail Reconnection

North-south asymmetries arise in the magnetosphere-ionosphere system when a significant east-west (By) component is present interplanetary magnetic field (IMF). During such conditions, By with same sign as IMF induced magnetosphere, and locations of conjugate footpoints are displaced between two hemispheres. It has been suggested that these introduced into closed magnetosphere by tail reconnection. However, recent studies instead suggest asymmetric lobe pressure induces asymmetries, which then reduced during periods enhanced To address this, we use Lyon-Fedder-Mobarry (LFM) model initiate loading-unloading cycle multiple runs changing IMF. Asymmetries loading phase unloading phase. The results thus low reconnection