Horizontal and vertical ocean currents
Ocean currents are horizontal or vertical movement of both surface and deep water throughout the world’s oceans (Briney, n.d.). The primary generating forces are wind and differences in water density caused by variations in temperature and salinity. Currents generated by these forces are modified by factors such as the depth of the water, ocean floor topography and deflection by the rotation of the Earth. Horizontal currents are wind driven, fast moving and carries small amount of water; while, vertical currents are slow moving, density driven and carries large bodies of water. In this paper I will describe horizontal and vertical currents, their importance and some of the tools used to measure ocean currents.
Horizontal ocean current or surface ocean current
Surface current are found in the upper four hundred meters (400m) and makes up about ten percent (10%) of ocean (Briney, n.d.). Surface ocean currents are as a result of friction between the water and atmosphere interface. The wind exerts a force or stress to the ocean surface and causes the water to move. The winds that most affect the oceans’ currents are the Westerlies which produce belts of ocean currents that flow east in the mid-latitude and the Trade winds which generate currents that flow to the west in tropical latitudes. These winds are mainly a result of warm air from the tropics moving towards the poles. The direction of the current is not the same as the direction of the wind but it is deflected at a forty five degree angle. This deflection is resulted from the earth’s rotation on its axis called the Coriolis force/ effect. Coriolis force and constrains by continental land masses cause surface currents to develop into an almost circular pattern called a gyre. These gyres move in a clockwise direction in the north and an anticlockwise direction in the south.
The major gyres are located thirty degrees north or south in the subtropical regions and are a result of high pressure system in the atmosphere. The minor gyres are found in the North Atlantic and North Pacific at fifty degrees north and are as a result of circulation low polar pressure system. The south does not form gyres because they lack continent.
Surface current of the subtropical gyres
To the north and south of the equator are the North and South Equatorial current respectively. These currents run from east to west and are deflected pole-wards when they encounter continents. The western boundary currents flow from the equator to high latitudes. These currents are warm, narrow, fast moving water. Western boundary currents are the strongest and deepest ocean surface flows. In the Northern Hemisphere, the east flowing North Pacific Current and North Atlantic Drift move the waters of western boundary currents to the starting points of the eastern boundary currents. The South Pacific Current, South Indian Current and South Atlantic Current provide the same function in the Southern...