Fig. 4

Result of applying several speed thresholds to 22–1 MLT data of Fig. 3. Speed thresholds are a 50 m/s, b 100 m/s, c 150 m/s, d 200 m/s, e 250 m/s, and f 300 m/s. Flows faster than the threshold are plotted as red crosses, whereas flows slower than the threshold are plotted as black squares