Geometric situation depicting a spacecraft passage through modeled magnetic clouds in Case 1.0. Two magnetic cloud systems are superposed, one (with the origin C) related to an expanding circular magnetic cloud and Fig. 6a, and the second one (with the origin E) related to an expanding elliptic magnetic cloud and Fig. 6b. The systems are aligned with the Y_c axes and the X_cY_c projections of the spacecraft trajectory (shown by the labeled straight vertical line). The X_c axes (not shown) are parallel to this vertical line and cross either the point C, or E. The solid-line circle and ellipse are magnetic-cloud cross sections at the spacecraft entry, while the dashed-line shapes display them at the spacecraft exit. The sense of the magnetic field rotation is shown by a bent arrow, and there is also B_Z component pointing toward the viewer (i.e., the field is lefthanded, h = −1).