What is Hoar Frost?
Frost is defined by many as the deposit of small ice crystals that form whenever water vapor is condensed at a temperature below freezing point. It happens whenever a solid surface freezes below the dew point of the air that surrounds it, and the surface becomes colder than freezing point, making frost form.
There are several different kinds of frost. One of them is hoar frost, also known as radiation frost, hoarfrost, or pruina. This refers to interlocking arrangement of white ice crystals that are deposited loosely on the ground or any exposed object forming on very cold nights whenever heat is lost into the sky causing objects to become colder than the air that surrounds it. Though most of the time, people’s misconception about hoar frost is that it is frozen dew, in reality, it is the result of the direct sublimation of gaseous water that later on becomes ice crystals. Dew is formed when the air mass is above freezing point.
Areas and surfaces that are prone to experience heavy fog are more likely to come into contact with hoar frost. It can cause grave damages to crops, plants, and some sensitive flowers, for it is in the surfaces of this plants that hoar frost initially forms.
The deposit of ice crystals that form on vegetation or other objects that are commonly mistaken to look like snow, hoar frost has many different names, each of which depends on where the hoar frost is formed. Air hoar is those that form on object surfaces. Examples of these are tree branches and stems of plants. Surface hoar looks like ice crystal ferns that are found on already frozen surfaces. They are caused by avalanches. Crevasse hoar are those that are located in glacier-like crevasses wherein water vapor forms even when there are calm weather conditions. Depth hoar is made up of cup-shaped crystals formed inside dry snow.
This kind of frost also forms around artificial environments such as industrial cold-storage facilities. Rooms that are not insulated against the cold or other areas where humidity and moisture enters and freezes instantly also form hoar frost.
The term hoar frost is believed to have come from a German word that means graying and old. The term expresses the white color of frost that is similar to the color of an old man’s beard.
The popularity of hoar frost increased due to its distinct appeal. Ragged and yet mysterious, hoar frost reminds people who take a closer look of a lacy ice crystal. The minute detail and intricacy of the design of the hoar frost makes it a very popular subject for contemporary artists. Hoar frost, when seen, most of the time gives off the feeling that one is in a winter wonderland.
In addition, one of the many misconceptions about hoar frost is that it is rime. Rime is frozen fog or glaze. When rime forms, it looks like a thick, continuous layer of ice, rather than individually frozen droplets that is hoar frost.