How the cusp features and the Alfven Transition Layer are affected by the IMF Rotation from North to dawn-dusk direction ?

Large-scale global three-dimensional PIC simulations are used in order to analyze the dynamics of the cusp boundaries and particle fluxes penetrating the cusp as the interplanetary magnetic field (IMF) rotates from northward to dawn-dusk direction. Recent 3D simulation works have been previously focussed on the formation of so called Alfven Transition Layer (ATL) located at the upper edge of the Stagnant Exterior Cusp (SEC) as evidenced originally in CLUSTER data (Lavraud et al., 2005) and on 3D dynamics of  electron / ion fluxes penetrating the cusp (Cai et al., 2015; Lembege et al., 2022), but  have been restricted to the northward direction of the IMF. The ATL is defined as a transition layer through which the plasma flow changes its bulk velocity from super-Alfenic regime (in the magnetosheath) to a sub-Alfvenic regime (in the ESC). The present work is an extension of these previous works and is focussed on the impact of the IMF rotation: (i) on the formation and the structure of the cusp itself, (iii) on the size, the location and the 3D features of the ATL, and (iii) on the 3D dynamics of the electron/ion fluxes when penetrating the cusp region. These preliminary results will be compared with those already obtained for a northward IMF.