Wake turbulence during air travel is caused by vortices generated by the wingtips of an aircraft. 1

As an aircraft flies, air moves faster over the top surface of the wing than the bottom, creating a difference in pressure. 2 When the higher pressure air below the wing seeks equilibrium with the lower pressure air above, it curls around the wingtips, creating vortices. 2

The strength of these vortices is directly proportional to the weight of the aircraft and inversely proportional to its speed and the wingspan. 2

Wake turbulence is especially hazardous in the region behind an aircraft in the takeoff or landing phases of flight, when the aircraft operates at a high angle of attack, which maximizes the formation of strong vortices. 4