**7. Velocity Characteristics during Conditional Events**

As mentioned in Section 2, simultaneous measurements of velocity using LDV above the hot-film are made for various wall-normal locations (shown in Table 1) at every Reynolds numbers studied. However, the wall-normal velocities were measured only for *Re<sup>τ</sup>* = 70 and 85, due to the limited access of the laser beams for LDV measurements closer to the bottom wall of the channel. Velocity information is also obtained using DNS in large computation domains (discussed in Section 3) for *Re<sup>τ</sup>* = 70 and 85. In this section, the criteria for conditional events are kept constant at Δ*t* + *cr* = 200 and *τw*/*τ<sup>w</sup>* < 0.9 for the low-drag events, and Δ*t* + *cr* = 200 and *τw*/*τ<sup>w</sup>* > 1.1 for the high-drag events, unless stated otherwise. To carry out the conditional sampling of the velocity data, we ensured that there are a sufficient number of conditional events (∼100) to obtain well-converged results. For the DNS, the number of high-drag events obtained were quite few in number, between 10 and 20 for both *Reτ* = 70 and 85. Therefore, the characteristics of only low-drag events are studied for the DNS data, whereas characteristics of both low-drag and high-drag events are studied using the experimental data.
