As most of you are aware, the temp is a changin. When I left for work this morning, I noticed a light frost coating on the grass and on my truck. So being the curious type, and also a lover of everything temperature related, (or as we like to call it – Distortion Sensitive Thermal Processing effects), I thought I’d do some digging and share what I found. Wow – way more cool info on frost than I expected. Some fun facts and some “techy” info for my science geeks out there. (Special thanks to Wikipedia and National Weather Services for info and images)
- Frost is the coating or deposit of ice that may form in humid air in cold conditions, usually overnight. In temperate climates it most commonly appears as fragile white crystals or frozen dew drops near the ground, but in cold climates it occurs in a greater variety of forms.
- Frost is composed of delicate branched patterns of ice crystals formed as the result of fractal process development. A fractal is a mathematical set that exhibits a repeating pattern that displays at every scale, also known as expanding symmetry or evolving symmetry.
- Frost forms when the temperature of a solid surface in the open cools to below the freezing point of water and for the most clearly crystalline forms of frost in particular, below the frost point in still air. In most temperate countries such temperatures usually are the result of heat loss by radiation at night, so those types of frost sometimes are called radiation frost.
- Different types of frost include crystalline hoar frost from deposition of water vapor from air of low humidity, white frost in humid conditions, window frost on glass surfaces, advection frost from cold wind over cold surfaces, black frost without visible ice at low temperatures and very low humidity, and rime under super cooled wet conditions.
- The size of frost crystals varies depending on the time they have been building up and the amount of water vapor available. Frost crystals may be clear or translucent, but, like snow, a mass of frost crystals will scatter light in all directions, so that a coating of frost appears white.
- Frost is known to damage crops or reduce future crop yields, therefore farmers in regions where frost is a problem often invest substantial means to prevent its formation.
- If a solid surface is chilled below the dew point of the surrounding humid air and the surface itself is colder than freezing, ice will form on it. If the water deposits as a liquid that then freezes, it forms a coating that may look glassy, opaque, or crystalline, depending on its type. Depending on context, that process also may be called atmospheric icing. The ice it produces differs in some ways from crystalline frost, which consists of spicules of ice that typically project from the solid surface on which they grow.
- The main difference between the ice coatings and frost spicules arises from the fact that the crystalline spicules grow directly from desublimation of water vapor from air, and desublimation is not a factor in icing of freezing surfaces. For desublimation to proceed the surface must be below the frost point of the air, meaning that it is sufficiently cold for ice to form without passing through the liquid phase. The air must be humid, but not sufficiently humid to permit the condensation of liquid water, or icing will result instead of desublimation. The size of the crystals depends largely on the temperature, the amount of water vapor available, and how long they have been growing undisturbed.
- As a rule, except in conditions where supercooled droplets are present in the air, frost will form only if the deposition surface is colder than the surrounding air. For instance, frost may be observed around cracks in cold wooden sidewalks when humid air escapes from the warmer ground beneath. Other objects on which frost commonly forms are those with low specific heat or high thermal emissivity, such as blackened metals; hence the accumulation of frost on the heads of rusty nails.
- The apparently erratic occurrence of frost in adjacent localities is due partly to differences of elevation, the lower areas becoming colder on calm nights. Where static air settles above an area of ground in the absence of wind, the absorptivity and specific heat of the ground strongly influence the temperature that the trapped air attains.
- To “frost” a mug, start with a “dry on the inside” thick walled glass. Set it in the freezer for at least 10 minutes. To speed it up, wrap it in a damp paper towel. If you don’t have a freezer, simply fill your glass/mug with ice and top it off with water. Wait about 6 minutes and then empty the ice/water and the sides will frost up.
- As some of you may remember, Frosty the Snowman was a 1969 animated Christmas television special based on the song “Frosty the Snowman”, which first aired on December 7, 1969 on CBS (where it still airs to this day). It was produced for television by Rankin/Bass Productions and featured the voices of comedians Jimmy Durante as the film’s narrator (Durante’s final performance in a film) and Jackie Vernon as the title character. Arthur Rankin, Jr. and Jules Bass wanted to give the show and its characters the look of a Christmas card, so Paul Coker, Jr., a greeting card and Mad magazine artist, was hired to do the character and background drawings.
Jack Frost is traditionally said to leave the frosty, fern-like patterns on windows on cold winter mornings (window frost or fern frost) and nipping the extremities in cold weather. He is sometimes described or depicted with paint brush and bucket coloring the autumnal foliage red, yellow, brown, and orange.
And a little throwback for my “hip” baby-boomers – Christmas tribute – Jack Frost & the Hooded Crow
So, it’s going to get pretty frosty this weekend. Send me one of your cool frosty photos and I’ll send you one of my hot KHT gifts.