Geography & History Notes | KCSE, NECTA, ZIMSEC & GCSE

  Ocean currents are general movements or drifts of the surface water of the ocean in a fairly defined direction. They are a continuous general movement of masses of surface ocean waters horizontally and in a fairly defined direction. They tend to be persistent. Most ocean currents drift very slowly and that is why they are commonly referred to as drifts. Ocean currents may be either warm or cold i.e. there are warm ocean currents and cold ocean currents.  The following are Causes of ocean currents The prevailing winds winds influence oceanic circulation; this is because as winds blow friction is generated between the wind and water surface causing the water to move in the general direction of the wind. Some winds such as trade winds which almost continuously blow in the same direction cause surface waters over which they blow to move in the direction to which they blow e.g. across the Atlantic ocean westerlies produce the North Atlantic drift and Kuro Siwo currents (in the Pa...

  Warm ocean currents are ocean currents with warm waters and may include the warm Mozambique current or the warm Agulhas current or South equatorial current in Africa. Other warm currents include; the warm gulf stream, the North Atlantic drift, the North Pacific current, the Kuro siwo current, the East Australia Current, the Brazilian current, and the Northeast monsoon drift.  Characteristics of warm ocean current: They have higher temperatures i.e. tend to be warm. They generally tend to flow on the eastern side of the continental landmasses in the low latitudes (except for Guinea current). They generally tend to flow on the western side of the continental landmasses in the mid and high latitudes e.g. the Pacific current and the North Atlantic drift. They tend to flow from the lower latitudes to the higher latitudes i.e. flow pole ward away from the equator. In the northern hemisphere, their circulation tends to be clockwise while in the southern, their circulation tends...