Currents

Synonyms

Not to be confused with electrical current; Ocean currents; Water flow

Definition

Currents are large-scale (mainly horizontal) translational motions of seawater, as opposed to the wave motions where water particles perform periodic back-and-forth excursions relative to the state of rest. Ocean currents can flow at great distances; they carry seawater and its inherent properties (heat and salt content, dissolved and particulate matter, etc.) from one region to another.

Ocean currents are expressed in terms of horizontal velocity (m/s) of fluid motion as a function of space and time, given either by the velocity vector components or by the direction and speed of the current. This is the Eulerian description of currents. Current velocity components are often presented as (eastward) zonal current and (northward) meridional current. When using the current presentation by flow direction, zero direction has been agreed for the current flowing to the north; the direction angle is...