| description:
|
Layer represents the geographic locations at which current (water
velocity) observations are presently being collected. Generally, "currents" are defined as a horizonal movement of water. Currents may be classified as tidal and nontidal. Tidal currents are caused by gravitational interactions among the sun, moon, and earth and are part of the same general movement of the sea that is manifested in the vertical rise and fall, called tide. Nontidal currents include the permanent currents in the general circulatory systems of the sea, as well as temporary currents arising from more pronounced meteorological variability. Most stations with current observations provide readings every 6 minutes. More information can be found at
http://tidesandcurrents.noaa.gov/cdata/StationList?type=Current+Data&filter=active |