Particle traces calculated in a Transient Data flow field are called pathlines.
Pathlines are simply Streamlines computed in a Transient Data flow rather than steady-state. Because of this, all computations and derivates must take into consideration the additional fourth dimension of the data - Time. This makes pathlines considerably more time-consuming and complex than streamlines, but more useful in analyzing flow over time.
A pathline in steady-state flow is identical to a streamline.
Pathlines are useful for visualizing the flow of an individual particle across time. Such uses for this include:
- Analyzing the paths of drifting debris in oceanographic data
- Analyzing paths of airborne debris or pathogens in atmospheric data
Visualizing a pathline is more difficult than a streamline, as each point coincides with not only a location but an additional time value. Because of this, visualization is typically as an animation, or as a time with annotated time information.
- Flow Description, Streamline, Pathline, Streakline and Timeline from "Aerodynamics for Students"
- Streamlines, Streaklines, & Pathlines on Wikipedia