Popular Posts

Tuesday, December 13, 2011


From Robert Southey’s Letters from England:

I looked out the window, everything was white, and the snowflakes like feathers floating and falling with as endless and ever varying motions as the dance of mosquitos on a summer evening. And this mockery of life was the only appearance of life; and indeed it seemed as if there could be nothing living in such a world. The trees were clothed like the earth, every bough, branch, and spray; except that side of the bark which had not been exposed to the wind, nothing was to be seen but was perfectly and dazzlingly white; and the evergreens in the garden were bent by the load. White mountains in the distance can give no idea of this singular effect.

Snow Science

What is snow? “Snow consists of ice crystals in the atmosphere which grow large enough to fall and reach the ground” (LaChapelle 3). There are two kinds of snow, that which falls from the sky (precipitated snow) and that which is produced by changes within deposited snow (metamorphosed). Of this latter, two are rime and hoar frost, which are ice crystals.

All precipitation starts as water vapor in the atmosphere. Whenever a parcel of air is sufficiently cooled, some of the water vapor condenses to form clouds. They may be water droplets or ice crystals. Most precipitation begins as ice particles. Under certain conditions, cloud droplets coalesce or ice crystals grow until they begin to fall. Snow crystals begin as ice particles which have formed around condensation nuclei (dust particles or minute crystals of sea salt). If formed in an atmosphere with an excess supply of water vapour (supersaturated air), they will continue to grow. If they fall through a cloud composed of supercooled water droplets, they will collect a coating of rime. Each water molecule consists of one oxygen and two hydrogen atoms. Hydrogen atoms provide bonds which hold together in a crystal lattice. This generates solid forms with hexagonal symmetry in one plane. Between 27ºF and 32ºF (-2.8ºC and 0ºC), for example, crystals take the form of six-sided plates. Below that, needles form.

On the basal plane, the plane of the crystallographic a-axes, there are three of these axes, each separated by 60° from the next. At a right angle to this plane is the crystallographic c-axis. Perfectly symmetrical snow crystals are in the minority. Frequently the crystals get coated with rime. Newly formed snow crystals have very unstable shapes. Even the most intricate snow crystals tend to become rounded particles of ice. This is a snowflake—the word snowflake is a general term that can refer to a single ice crystal, a small cluster of them or a large aggregation that forms when crystals “collide and stick in midair, falling to earth in a flimsy puffball” (Libbrecht). Most snow crystals are tiny, but huge ones do exist. Recent research has shown that unusually large snowflakes, two to six inches wide, fall regularly, but many go un-witnessed and it is hard to authenticate them. For example, the Guinness Book of World Records gives a storm in January 1887 in Fort Keogh, Montana, as evidence of the largest recorded snowflakes. A rancher nearby measured the flakes at 15 inches wide.

According to Dr. Libbrecht of Caltech, a snowflake expert, the laws of physics suggest no obvious restrictions on the size of large flakes, but wind can easily break down fragile snowflakes of any size. (Note that top speed for the average snowflake can reach 1.7 meters per second.) Scientists are still learning about the way atmospheric conditions reflect the formation of snow. For example, in the daytime, thick clouds full of snow crystals reflect sunlight, keeping things cool below; however, at night, the clouds keep the heat in.

The infinite amount of snowflakes that have fallen and will fall seems to assure us that no two snowflakes are, actually, exactly alike. David Phillips, the senior climatologist with Environment Canada, has estimated that the number of snowflakes that have fallen on Earth over the course of time is 10 followed by 34 zeros.

Snow Facts

• The world’s largest snowman was built in Bethel, Maine in 2008. It was a actually a snowwoman at 122 feet tall.
• In the US, New York State cities receive the most snowfall, with Rochester and Syracuse leading with 93 and 115 inches per year respectively.
• Almost 187 inches of snow fell in seven days on Thompson Pass, Alaska, in February 1953.
• Practically every location in the US has seen snow, even areas in Florida.
• The greatest snowfall officially reported at the Phoenix, Arizona by the National Weather Service Office was one inch.
• Prior to 2009 and 2010, snow-heavy years in Britain included 1991 (on the night of February 7th, 25 cms fell in London); 1981-2 (when transport systems went berserk and prevented commuters from getting to work for two days straight; some homes in Somerset were without electricity for five days); 1962-3 (when blizzards affected most of the UK and London had 12 inches of snow); 1946-7 (one of the snowiest winters in British history); and 1925, when six foot walls of snow greeted people trying to dig themselves out, and a radio hoax was perpetrated.
• For weather-observing purposes, the intensity of snow is characterized as 1) light when the visibility is 1 km; 2) moderate when the visibility is less than 1 km but not more than ½ km; and 3) heavy when the visibility is less than ½ km.
• Funagata, Japan, has a climate of extremes, where days in winter are short and cold, but temperatures soar in the summer. In 1987, officials of the farming community in northern Yamagata Prefecture started looking for creative ways to use their abundant snowfall as a source of clean energy. Beginning in 1990, they began experimenting with snow-cooled storehouses for preserving farm produce. Rice stored for one year tastes just as good as newly harvested rice. Funagata officials have also constructed an experimental air-cooling system using an underground “icehouse.”

Baltimore Snowballs

There’s No Business like Snow Business

Some collected poems about snow.

. . . like mattresses inside abandoned mini-bars
where, deep within the vales of blue snow,
loneliness has built her secret palaces
that glitter like the tears of billionaires
nobody will ever find their way to:
the corridors are long,
the stairs are icy,
the lifts controlled by grubby-looking angels
who spend their days alone on distant landings
crushing heads between the closing doors.
Selima Hill

Vivaldi – Winter

Blank white page of Ty Newydd in the snow,
then, two trails of footprints across the lawn:
a poem or a story soon begins to grow,
tiny bird-claw messages like scratching of thorn.
The half-circle, half-cone of the bay-window,
so far from the toy-town of Portmeirion,
the frames are five negatives of a photo,
images just waiting to be born.
Inside, by a crescent-chair, is the voice-mirror,
The very place where Lloyd George died:
his tones living one second after,
a sound like the back-flow of the tide.
Each word you read from there
becomes a crystal, floating through air.
Mike Jenkins

One must have a mind of winter
To regard the frost and the boughs
Of the pine-trees crusted with snow;

And have been cold a long time
To behold the junipers shagged with ice,
The spruces rough in the distant glitter

Of the January sun; and not to think
Of any misery in the sound of the wind,
In the sound of a few leaves,

Which is the sound of the land
Full of the same wind
That is blowing in the same bare place

For the listener, who listens in the snow,
And, nothing himself, beholds
Nothing that is not there and the nothing that is.
Wallace Stevens

And did you know
That every flake of snow
That forms so high
In the grey winter sky
And falls so far
Is a bright six-pointed star?
Each crystal grows
A flower as perfect as a rose.
Lace could never make
The patterns of a flake.
No brooch
Of figured silver could approach
Its delicate craftsmanship. And think:
Each pattern is distinct.
Of all the snowflakes floating there –
The million million in the air –
None is the same. Each star
Is newly forged, as faces are,
Shaped to its own design
Like yours and mine.
And yet… each one
Melts when its flight is done;
Holds frozen loveliness
A moment, even less;
Suspends itself in time –
And passes like a rhyme.
Clive Sansom


National Snow and Ice Data Center.
“Snow Britain.”
“Snow Poems and Poetry.”

No comments:

Post a Comment