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Current (Hydroform Class)

Component: Hydroform

Unique Identifier: 627

Hydroform Class Current
Hydroform Boundary Current
Buoyancy Flow
Current Meander
Deep Boundary Current
Deep Circulation
Deep Convection
Density Flow
Ekman Flow
Inertial Current
Langmuir Circulation
Mean Surface Current
Mesoscale Eddy
Residual Current
Sub-mesoscale Eddy
Thermohaline Eddy
Tidal Flow
Turbidity Flow
Wave-driven Current
Wind-driven Current


Description
Definition Water that is undergoing coherent mass movement, either as laminar or turbulent flow, relative to surrounding waters and fixed structural, landform or geologic features. A directional, coherently flowing water mass. Currents operate on a wide range of temporal and spatial scales from huge ocean gyres and major surface and deepwater currents of the ocean operating on annual timescales to tidal currents that operate on sub daily timescales. However, all currents have features in common: the advective movement and transport of water, constituents (such as particulates and dissolved compounds), qualities (such as temperature and salinity) and biota (such as plankton, nekton, and megafauna). Currents are driven by gravity flow, geostrophic flow, density differences, hydraulic differential or energy input. They may be isolated from land and freely flowing in the water column as is the Gulf Stream, or they may be in channelized flow or long-shore flow. Currents that impact land also shape the littoral zone or sea bottom by winnowing sediments, physically mixing or shearing substrates and biota and creating geoforms such as sand ripples and bars.