| A | B |
|---|
| ebb current | When a tidal current moves toward the sea away from the land |
| flood current | When a tidal current moves toward the land and away from the sea |
| rectilinear current | tidal currents that ebb and flood in opposite directions |
| slack water | period of no velocity as tidal currents move from the ebbing to flooding stage, and vice versa |
| spring currrents | When the moon is at full or new phases, tidal current velocities are strong |
| neap currents | When the moon is at first or third quarter phases, tidal current velocities are weak |
| apogean currents | When the moon and Earth are at their farthest distance from each other, the currents are weaker |
| perigean currents | When the moon and Earth are positioned nearest to each other, the currents are stronger than average |
| wind duration | how long the wind blows |
| fetch | distance over water that the wind blows in a single direction |
| breakers | Waves that become too steep and unstabl |
| longshore currents | currents are generated when a "train" of waves reach the coastline and release bursts of energy |
| rip currents | localized current that flows away from the shoreline toward the ocean, perpendicular or at an acute angle to the shoreline |
| upwelling | occurs when winds blowing across the ocean surface push water away from an area and subsurface water rises up to replace the diverging surface water |
| downwelling | when wind causes surface water to build up along a coastline and the surface water eventually sinks toward the bottom |
| Coriolis effect | the deflection of circulating air and water caused by the rotation of the earth |
| Eckman spiral | structure of currents or winds near a horizontal boundary in which the flow direction rotates as one moves away from the boundar |
| Eckman layer | layer of water affected by surface wind |
| tradewinds | A wind blowing steadily toward the equator from the northeast in the northern hemisphere or the southeast in the southern hemisphere, esp. at sea |
| intertropical convergence zone | Zone (also called the doldrums) between 5 degrees North and 5 degrees South latitude, where the winds are calm |
