Spiraling of adjacent trajectories in chaotic systems
  The spiraling of adjacent trajectories in chaotic dynamical systems can be characterized by distribution of local angular velocities of rotation of the displacement vector, which is governed by linearized equations of motion. This distribution, akin to that of local Lyapunov exponents, is studied for three examples of three-dimensional flows. Toy model shows that the rotation rate of adjacent trajectories influences on the rate of mixing of dynamic variables and on the sensitivity of trajectories to perturbations. 
P.V. Elyutin