The Role of Vortices in the Formation of the Solar System: the Effect on Dust Particles
A. V. Mehta, G. R. Flierl (MIT)
Numerical calculations show that a long-lived, robust vortex can persist in the solar nebula. The stable vortex has a negative vorticity (relative to the orbital angular velocity), which is the same sign as the Keplerian shear. If several negative vortices are close to each other, they will merge to form a larger vortex.
Dust particles suspended in the gas will tend to be expelled from a
positive (unstable) vortex and drawn into a negative vortex. A 
-sized particle will be mostly locked with the vortex, with a small
drift component. A cm-sized particle will drift faster, reaching the
middle of the vortex in about 
. The differential drift
velocity increases the number of collisions, enhancing aggregation into
larger particles.