Solar wind speed structures at 1 AU during CR 2070-2071. The first row shows the synoptic maps of solar wind speed between latitude ±45°. From left to right, the maps are obtained at the start of CR 2070, the start of CR 2071 (also the end of CR 2070), and the end of CR 2071. Trajectories of STB (green), L1 (blue) and STA (red) during CR 2070 are imposed on the first map, and the trajectories during CR 2071 are imposed on the second and third maps. The second row shows the comparison between simulated and observed solar wind speed at the position of STB (first column), L1 (second column) and STA (third column). The simulated results are represented by black scatters. The observed data are presented by green (STB), blue (L1) and red (STA) color. Results sampled by the virtual spacecraft are represented by pink (STB-S5, STA-N5) and purple (STB-S10, STA-N10). The third row shows solar wind speed mapped to the L1 point. The left and right panels are observed data and simulate results, where STB, L1 and STA are represented by green, blue and red color.