- Absorption of Radiatio: As the sun rises, its shortwave radiation, including visible light and infrared radiation, penetrates the fog. The fog droplets absorb this radiation and convert it into heat energy.
- Heating and Evaporation: The increased temperature leads to the evaporation of water droplets within the fog. As the water droplets absorb heat, they gain kinetic energy, breaking the weak bonds that hold them together. This causes individual droplets to transform into water vapor.
- Rising Air Mass: The heating effect of sunlight also creates a warmer air mass near the ground. This warmer air has a lower density than the surrounding cooler air, causing it to rise. As the warm, moisture-laden air rises, it encounters decreasing atmospheric pressure at higher altitudes. This decrease in pressure allows for further expansion of the air, promoting evaporation.
- Dispersal and Thinning: As the fog droplets evaporate, the density and visibility of the fog gradually decrease. The once dense fog bank starts to thin out, revealing objects at a distance that were previously obscured.
- Variable Clearing: The process of fog dissipation can vary in speed and completeness. Some fog layers might dissipate entirely within a few minutes or hours, while others might take longer to clear, depending on factors like temperature, humidity, wind speed, and the thickness of the initial fog layer.
In summary, after sunrise, the increasing solar radiation heats the fog droplets, leading to their evaporation. This heating effect creates warmer, buoyant air that rises and disperses the fog, resulting in improved visibility and clearing skies.
