1. Ocean currents are actually horizontal water movements caused by many different factors or combination of them. Some of them are:
• Wind – Strong winds (such as the Westerlies and the Trade Winds) can move the water surface causing the ocean currents.
• Water Density (the difference in water dense is due to difference in water salinity and temperature) - more dense water will sink and that sinking water pushes the water below it up.
• Topography of the ocean bottom - ridge in the ocean bottom moves the water upward, while valley in the ocean moves it downward.
• Coriolis Effect - refers to an internal force (Coriolis) that causes the deflection of an object in motion. As a consequence of this effect, objects in the Northern Hemisphere of the Earth are deflected to the right and objects in the Southern Hemisphere to the left.
2. Coriolis force is an internal force that acts on objects in motion and it is responsible for many weather occasions. Deflection of an object under the influence of Coriolis force is called the Coriolis effect. The Coriolis force causes the movement of objects in the Northern Hemisphere of the Earth to be deflected to the right and to the left in the Southern Hemisphere. So, there are two currents of water movements in opposite directions one in the Northern Hemisphere; the other in the Southern hemisphere and when these currents are deflected by land masses ocean currents are formed.
3. The ocean current can affect climate in many different ways. For example, warmed or cooled water carried by ocean currents can travel for very long distance. The displaced warm water will raise the temperature of the air while the cold will cool it. So, some currents take warm water away from the equator, to the poles where they influence coastal climates. On the other side colder water from the poles moves towards the equator cooling the air above and absorbing the heat.
