Oceanography

Definition and Features

1.Ocean Currents are the large scale water movement which occurs everwhere in the ocean.  Ocean currents relay on atmospheric circulation for their propulation.

2.Current table tables that give daily predictions of times, speed, and direction of tidal currents. 

3.Ebb current: Tidal current directed away from shore or down a tidal stream.

4.Density current flow caused by density differences or gravity of one current under, or over another current. It retains its unmixed identity from the surrounding water because of density differences.

5.Ekman spiral: representation of currents resulting from a steady wind blowing across an ocean having unlimited depth and extent uniform viscosity. The surface layer move 45° to the right of the wind direction in the Northern Hemisphere. Water at successive depths drifts in directions more to the right until, at some depth, the water moves in a direction opposite to the wind water. Speed decreases with depth throughout the spiral. The net water transport is 90° to the right of the wind in the northern hemisphere.

6.El Nino warm surface waters offshore from Peru. It occurs around Christmas time. 

7.Geostrophic current current resulting from the balance between gravitational force and the Coriolis effect.