Jesse and I stopped by Lake Johanna on our way to work this morning. The fog was visually stunning:
Fog forms over bodies of water when the atmospheric temperature drops below the water temperature. The vapor pressure of the warm water is greater than the vapor pressure of water vapor in the air. Thus there is a movement of water into the air, which immediately condenses as it mixes and gets cold. Sun “burns off” fog by raising the temperature of the air. As the air temperature increases it’s vapor pressure also increases — which means that it can hold more water.
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