The temperature of the Earth’s atmosphere changes throughout the day and night, and is influenced by many factors, including solar radiation, clouds, wind, and more. One of the most significant factors affecting temperature fluctuations is the Earth’s rotation, which results in the daily cycle of daytime and nighttime.
During the daytime, the sun provides a constant source of energy, heating the Earth’s surface and the air above it. The land and water absorb and radiate this heat, warming up the surrounding atmosphere. This heating effect is most intense during the late morning and early afternoon when the sun is highest in the sky, and the solar radiation is the strongest.
At night, the absence of sunlight means that the Earth’s surface cools down, and so does the surrounding air. Without the sun’s energy, the surface of the Earth radiates the heat it has absorbed back into space. As a result, the temperature drops, and the air near the ground becomes cooler than during the day.
Another factor that contributes to lower temperatures at night is the lack of mixing of the atmosphere. During the day, the sun heats the ground, which in turn heats the air near the ground. This warm air rises, and cooler air sinks, creating convective currents that mix the air and distribute the heat. At night, these convective currents weaken or stop altogether, resulting in a stable atmosphere where the warm air at the surface remains close to the ground, and the cooler air remains aloft.
The lack of sunlight and the absence of convective currents also lead to the formation of temperature inversions, where the temperature increases with height instead of decreasing. This phenomenon occurs when the air near the ground cools down faster than the air above it, leading to a layer of cold air trapped beneath a layer of warm air.
Overall, the temperature is lower at night than during the day because of the absence of solar radiation and convective currents, and the cooling effect of radiating heat back into space. Understanding these factors can help predict and prepare for changes in temperature, which has important implications for agriculture, energy use, and human health.