Trajectory (fluid mechanics)
In fluid mechanics, meteorology (weather) and oceanography, a trajectory traces the motion of a single point, often called a parcel, in the flow. Trajectories are useful for tracking atmospheric contaminants, such as smoke plumes, and as constituents to Lagrangian simulations, such as contour advection or semi-Lagrangian schemes.
Source: Wikipedia — Trajectory (fluid mechanics) (CC BY-SA 4.0)