The ocean stores radiation from the sun and it also helps to distribute heat around the globe. When the sun warms the water, the water molecules are heated and they freely exchange freely with the air using the evaporation process. Since solar energy is constant around the globe, the ocean water always warming and is constantly evaporating. The evaporation increases the temperature and humidity of the surrounding air. This forms rain and storms that are then carried by trade winds, often vast distances. In fact, almost all rain that falls on land starts off in the ocean. The tropics are particularly rainy because heat absorption, and thus ocean evaporation, is highest in this area.