Why does most of the water in air come from oceans and sea?

The vast majority of water vapor in the air comes from the ocean. This is because water evaporates more readily from the surface of water than from other surfaces, such as land or vegetation. The process of evaporation is driven by the sun's energy, which causes water molecules to move faster and break away from the liquid water.

The rate of evaporation depends on a number of factors, including the temperature of the water, the humidity of the air, and the wind speed. In general, evaporation occurs more quickly in warm, humid conditions and in windy conditions.

The oceans cover about 70% of the Earth's surface, so they are the largest source of water vapor in the air. The air over the oceans is typically warm and humid, which makes it ideal for evaporation. Additionally, the winds that blow over the oceans help to transport water vapor away from the surface of the water, preventing it from becoming too concentrated in one area.

As water vapor rises into the atmosphere, it cools and condenses into clouds. The clouds then release the water vapor as precipitation, such as rain or snow. This precipitation falls back to the Earth, where it can either be absorbed by the ground or flow back into the oceans.

The water cycle is a continuous process that keeps the Earth's climate regulated. Without the oceans, there would be much less water vapor in the air and the Earth would be a much drier place.