Solar radiation: Solar radiation is the energy emitted by the sun in the form of electromagnetic waves. When sunlight reaches the Earth's surface, it is absorbed by various objects, including sand. The energy from the sunlight is converted into heat, which causes the sand to become warm.
Heat transfer: Once the sand has absorbed the sun's energy, it begins to transfer heat to the surrounding environment. This heat transfer occurs through conduction, convection, and radiation. Conduction is the transfer of heat through direct contact between two objects. For example, when you sit on the warm sand, heat from the sand is transferred to your body through conduction. Convection is the transfer of heat through the movement of a fluid. For example, when the wind blows over the sand, it carries away some of the heat from the sand. Radiation is the transfer of heat through electromagnetic waves. For example, the sand emits infrared radiation, which can be felt as warmth on your skin.
Cooling at night: At night, the sun is no longer present to provide heat, so the sand begins to cool down. The sand loses heat to the surrounding environment through conduction, convection, and radiation. The air temperature at night is often cooler than during the day, which further contributes to the cooling of the sand. As a result, the sand at the beach is warm during the day and cool at night.
