Stokes drift
![An expanse of driftwood along the northern coast of Washington state. Stokes drift – besides e.g. Ekman drift and geostrophic currents – is one of the relevant processes in the transport of marine debris.[1]](/uploads/202502/13/Driftwood_Expanse,_Northern_Washington_Coast3819.png)


For a pure wave motion in fluid dynamics, the Stokes drift velocity is the average velocity when following a specific fluid parcel as it travels with the fluid flow. For instance, a particle floating at the free surface of water waves, experiences a net Stokes drift velocity in the direction of wave propagation.