Why are wingtip vortices stronger when airspeed is lower?

Question

Why are wingtip vortices stronger when airspeed is lower?

Answer 1

Vortices's are created due pressure differential between the upper and lower surface of the wing.  Therefore, strength of wing tip vortices's is directly related to the the amount of lift being created by a wing.  At slower air speeds in a high lift configuration the pressure differential is greater than at higher speeds thus resulting in stronger wing tip vortices's.

Answer 2

The vortex is stronger because of the high angle of attack.  The slow indicated airspeed is just coincidental.

Answer 3

At higher airspeeds, the slipstream pushes the vortices back and makes them narrower.  "Blows them away."

Answer 4

As lift increases with an increase in angle of attack, induced drag also increases. This occurs because as the angle of attack is increased, there is a greater pressure difference between the top and bottom of the wing, and a greater lateral flow of air; consequently, this causes more violent vortices to be set up, resulting in more turbulence and more induced drag.

The  strength of the wingtip vortices is directly proportional to the weight of the airplane and inversely proportional to the wingspan and speed of the airplane.

The heavier and slower the airplane, the greater the angle of attack and the stronger the wingtip vortices. Thus, an airplane will create wingtip vortices with maximum strength occurring during the takeoff, climb, and landing phases of flight.