The icy fog this morning led to a dazzling display of scenery through the area while the trees were covered with ice.
Was this frosted ice or frosted ice? This is a big question we received. The difference between the two has to do with the physical phase change of water.
Rime Ice
Rime ice is caused by a phase change from supercooled liquid water to ice. I explained in a blog post last night what chilled water is. You can read it here.
Many clouds (and the fog last night) consist of liquid water droplets occurring below freezing. The temperature was well below freezing last night, which means that when the subcooled liquid water droplets made contact with solid objects below the freezing point, it froze.
The icy trees were therefore this morning the result of frost ice through dense freezing fog. Freezing fog is a primary cause of frostbite.
Frostbite can be hard or soft and usually depends on the wind speed. A stronger wind will result in hard lime that looks thicker and more compact to soft lime. Soft lime looks more feathery and fragile and looks like frost.
Hoar Frost
Hair ripening is caused by a phase change of gaseous water vapor directly in ice when the air reaches the ripening point through cooling. It is similar to dew, but if the temperature is below freezing. It is not liquid dew that freezes. This type of frost usually occurs in a cold, clear and calm night in the presence of sufficient moisture.
