Example of a localized subregion in the LS layer during the nonlinear stage. Left: 3D visualization of the electron velocity distribution function (VDF) in the selected box, shown in (v_∥, v_⊥,1, v_⊥,2) space. The VDF exhibits a clear elongation along the magnetic field direction and a double-core structure. Top row: 2D projections of the VDF in the (v_∥, v_⊥,1) and (v_∥, v_⊥,2) planes. Middle row: spatial maps of electron agyrotropy (﹩\sqrt{{Q}_{e}}﹩) and parallel electron heating (T_∥,e/T_∥,e0). Bottom row: electron mixing fraction (F_e) and ﹩{\mathrm{log}}_{10}| {J}_{z,e}| ﹩, with the analyzed subregion highlighted by the magenta box.