  In the present paper, we study transport properties of coherent vortices.
These structures are formed by tubes of fluid parcels that complete similar
material rotation. Here, we demonstrate that time $t_0$ positions of such
physical structures can be identified from the angular momentum along their
trajectories. We identify and extract these Lagrangian vortices as material
domain in which fluid elements complete similar Lagrangian angular momentum
around the same axis and over the same finite time duration. The present method
shows high vortices' monitoring capacity by identifying automatically all
coherent clockwise and counterclockwise vortices. The performance of the
proposed method is illustrated over different two- and three-dimensional flows.
