The sun plays a vital role in maintaining our climate here on earth. The sun releases large amounts of energy in the form of solar radiation towards earth. Some of this energy is reflected back towards space, while some in absorbed by Earth. Our oceans absorb much of this solar radiation; water molecules in the ocean become heated and begin a process called evaporation, in which water turns to vapor within the air. This process increases the temperature of the surrounding air that is then carried by trade winds great distances. These surface winds play a large role in driving ocean currents. The ocean currents act as a sort of conveyor belt; they carry warm water and precipitation from the equator towards the poles of earth.

Cold water is carried in the opposite direction from the poles to the equator. This circulation pattern is what ultimately regulates global climate. In summary, solar radiation absorbed by the oceans create warm temperatures carried by wind around the globe and also create warm ocean temperatures that are dispersed around the globe via the ocean conveyor belt.

The sun creates wind by heating the ground, which heats the air above it, which then causes the heated air to rise. The rising heated air creates a vacuum underneath it as it rises, so that air from the surrounding side rushes in to fill the hole - this is wind. Then, when the warm air cools off at high altitude, it sinks or is carried down along with rain by gravity, pushing the air down at the ground out of the way, creating more wind.

The sun does not cause ocean currents. This is because the sun only heats the surface of the sea, which is already at the top of the ocean and so can't rise any further. Ocean currents are instead mainly caused by the fact that the Earth is rotating (by the way, much of the wind is caused by the Earth's rotation as well).

There are 2 forces that cause wind and ocean currents. 1 --the sun. The sun sends rays of light and heat to the earth. The heat contributes to the currents, by convection. When we say that "heat rises", we are talking about convection.

Convection is the movement of hot gas/liquid up, while the cool gas/liquid down (think of why the top level of a house is always much warmer than in the basement). The heat from the sun causes convection of the oceans and in the air systems. Adding heat forces the ocean and air masses to mix, and circulate.

2-- the earth rotates. The earth orbits the sun, but also each day is marked by one rotation of the earth. These movements are very slow so we don't notice, but the earth rotating actually produces a really strong force, which we call "the Coriolis force". This also affects the ocean and air currents.