Q.20. Mention the factors responsible for the origins of ocean currents and name the currents of the Atlantic Ocean.

An ocean current is a continuous, directed movement of seawater generated by several forces acting upon the water. Ocean currents play a crucial role in determining climates of coastal regions. They can be warm or cold, affecting temperature variations in different areas.

Factors Responsible for the Origin of Ocean Currents:

1. Planetary Winds:
   • Planetary winds play a crucial role in driving ocean currents. These winds push surface water along with them, creating currents.
2. Difference of Density and Salinity:
   • Variations in density and salinity within ocean water motivate denser waters to sink and move as undercurrents, while lighter waters move as surface currents.
3. Rotation of the Earth (Coriolis Force):
   • The rotation of the Earth generates the Coriolis force, which affects the direction of water movement and leads to the formation of ocean currents.
4. Shape of Coastline:
   • The shape of the coastline also influences ocean currents. Coastal features can obstruct or guide the flow of water.
5. Frictional Force:
   • Friction between water layers and surrounding fluid affects the speed and direction of ocean currents.

Major Currents in the Atlantic Ocean:

1. North Equatorial Current (Warm):
   • Flows from east to west between the equator and 10°N latitude.
   • Originates due to upwelling of cold water near the west coast of Africa.
   • Bifurcates into the Antilles current (flows east of the West Indies islands) and the Caribbean current (enters the Gulf of Mexico and becomes the Gulf Stream).
2. South Equatorial Current (Warm):
   • Flows from the western coast of Africa to the eastern coast of South America between the equator and 20°S latitude.
   • Stronger and more extensive than the north equatorial current.
   • Bifurcates into the northward branch (merges with the north equatorial current near Trinidad) and the southward branch (continues as the Brazil warm current parallel to the east coast of South America).
3. Counter-Equatorial Current (Warm):
   • Flows from west to east between the strong north and south equatorial currents.
   • Known as the Guinea Stream in the east.
   • Carries relatively higher temperature and lower density than the equatorial currents.

These currents significantly influence regional climates, fishing grounds, navigation, and oceanic ecosystems. Understanding their dynamics is essential for various aspects of human activity and environmental management.