An ocean current is a continuous, directed movement of the seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling and temperature and salinity differences. depth contours, shoreline configuration, and interaction with other currents influence a current’s direction and strength. ocean currents are primarily horizontal water movements.
Warm ocean currents are ocean currents that move warm water from the equator. Warm current has warm water therefore they are less dense than cold water.
Warm ocean currents have influenced the climate or environmental conditions of the areas adjacent to them in the following ways;
- They lead to warm conditions, i.e. they tend to warm or raise the temperature of the adjacent area, this is because the winds which blow over them are warmed up and as they blow onshore they bring in warm conditions e.g. the North Atlantic drift raises the temperatures of the coasts of Portugal, France, Britain, the Netherlands etc. and the ocean ports remain ice free in winter. Durban on the eastern coast of South Africa is affected by the warm Mozambique current and has temperatures of 24.40C compared to Port Noloth on the west coast along the same latitude which has temperatures of 15.50C because of the cold Benguela current.
- Warm ocean currents lead to heavy rainfall conditions on the adjacent coastal lands. This is because over warm ocean currents there is high rate of evaporation and the winds that blow over them pick the moisture which winds later rise, cool down and condense to form rainfall e.g. along the East Africa coast and along the west African coast there is heavy rainfall because of the warm Mozambique and warm Guinea currents respectively. For instance Beira receives 1,521 mm and Durban receives 1,008 mm of rainfall per annum.
- They results into humid conditions, i.e. high humidity. This is because warm ocean currents are associated with high humidity due to the relatively high temperatures. All these tend to increase the humidity of the surrounding areas e.g. the Natal Province of South Africa and the coasts of Western Europe.
- Warm ocean currents influence the temperatures of winds and result into warm winds. Winds that tend to originate from areas with warm currents are generally regarded as warm maritime winds.
- They lead to increased cloud cover over the adjacent coastal lands. This is because of the high rate of evaporation. The water vapour rises, cools and condenses to form dense clouds (cumulonimbus clouds) which later result into heavy rainfall.