The reduction of aerodynamic drag is a strategic objective to decrease energy consumption and pollutant emissions in modern transportation systems. In high performance vehicles, such as commercial aircraft, more than half of the total drag is caused by surface skin friction. Studies aimed at characterizing the coherent structures of the turbulent boundary layer [1–3] have demonstrated that the primary contributors to wall shear stress are structures known as sweeps, events consisting of high, speed fluid directed toward the wall from the outer region. To mitigate surface friction, active control techniques focused on reducing the frequency and intensity of these wall-ward sweep events have proven highly effective.