In the ancient world, life was very much tied to events and activities in the sky. These societies often regarded the sun as a deity, and his daily and monthly journeys were closely watched. The winter solstice marked the end of the sun's journey to the south, an event that held the promise of a new year as the sun began its slow return to a higher position in the sky.
This annual return of the sun from north was a signal of the earth's imminent rebirth from the barren days of winter. Important religious festivities celebrated the sun's annual change of course. With this change came an affirmation that the cycle of life was not broken and that winter would pass.To ancient agricultural societies, the beginning of a new solar year was a significant event. It implied the promise of a new planting season that the longer days and warmer weather would bring. Since life was so dependent upon agriculture, it seems appropriate that celebrations accompany the astronomical events marking the change of the seasons.
Central heating, electric lights and supermarkets make winter just an inconvenience for us. Winter does not bring the threat of hardship and famine that it did to our ancient ancestors. But our present-day celebrations have a direct link to these ancient cultures.
Though it occurs more than a week later than the actual solstice, the beginning of our new year is obviously associated with the solstice and the beginning of a new solar year. In many ways, New Year celebrations are re-enactments of the ancient solstice festivities.
The celebration of Christmas has a less obvious but direct link to the winter solstice. Christmas is, of course, the celebration of the birth of Jesus Christ, but to the ancient Romans Dec. 25th was the festival of Dies Invicti Solis (the Day of the Invincible Sun). This Roman celebration of the winter solstice honored Sol, the Roman god of the sun. In fact, the word solstice means Sol standing, an obvious reference to the end of the sun's journey and its imminent return.
Shortly after Christianity's sweep over the Roman Empire, many ancient pagan holidays were eliminated or replaced with Christian holidays. It must have seemed fitting to these early Christians that the holiday celebrating the Roman sun god Sol and the birth of a new year should be replaced by a holiday celebrating the birth of Christ and the beginning of a new era.
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Winter solstice occurs when the earth's northern hemisphere reaches its maximum annual tilt away from the sun (see chart below). This year, solstice happens on Tuesday, Dec. 21, at precisely 1:27 p.m. MST, marking the official start of winter. It also coincides with the longest night of the year and the day on which the sun traces its southernmost path across the sky.
In the southern hemisphere the solstice marks the beginning of summer. This is because when the northern hemisphere reaches its maximum tilt away from the sun, the southern hemisphere reaches its maximum tilt toward the sun. Next June 21 summer solstice will mark the beginning of our summer and their winter.
Curiously, the coldest part of the year does not coincide with the winter solstice and the shortest days of the year. In Utah, the coldest average temperatures usually occur in mid-January. Before then, the oceans, atmosphere and ground are still releasing heat accumulated during the previous season. This release of heat keeps the temperature during fall and early winter slightly warmer than it otherwise would be.
This effect is especially pronounced along coastal areas. Here, the coldest time of the year is often delayed several weeks due to the moderating effects of residual heat in the oceans.
During the latter part of January, the lengthening winter days cause a warming that overtakes the diminishing release of heat left from the past season. This results in a slow net accumulation of heat, and average temperatures begin to rise.
Once again, the cycle has continued unbroken. There is hope for brighter days ahead.
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ADDITIONAL INFORMATION
Snow crystals:
STELLAR CRYSTAL
NEEDLE
HEXAGONAL COLUMN
CAPPED COLUMN
SPATIAL DENDRITE
IRREGULAR CRYSTAL
HEXAGONAL PLATE
Snow crystals are small ice crystals that form inside clouds from water vapor. These crystals grow in 6-sided platelike and columnar patterns. Temperature, humidity and other weather conditions inside the cloud determine the exact shape of the snow crystal.
Liquid water is not involved in the formation of snow crystals; the change is directly from vapor to solid. Snow crystals form when vapor accumulates on microscopic particles callecd ice nuclei. As the snow crystals grow, they get heavier and eventually break free from the clouds and fall to the earth as snow.
Snowflakes form when snow crystals begin to stick together in clumps. Often, a snowflake is made from dozens of snow crystals.
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Record snowfall
The record for the most snowfall in a single year in the U.S. occurred at Rainier Paradise Ranger Station in Washington. 1,122 inches (93.5 feet) of snow fell during the winter of 1972-73.
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Winter trivia
COLDEST RECORDED TEMPERATURE IN UTAH:
-69 degrees F. at Peter Sinks at the top of Logan Canyon, Feb. 1, 1985.
COLDEST RECORDED TEMPERATURE IN THE UNITED STATES:
-80 degrees F. at Prospect Creek, Alaska, on Jan. 23, 1971.
COLDEST RECORDED TEMPERATURE ON EARTH:
-128.6 degrees F. at Vostok Station in Antarctica, July 21, 1983.
UTAH'S WORST WINTER:
The winter of 1948-49. Only 18 hours of temperatures above freezing were recorded in Salt Lake City during January. Snowfall totaling nearly 80 inches caused livestock losses of up to 25 percent. OPERATIONS HAYLIFT supplied feed to thousands of sheep stranded on Utah's western desert.
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The solstice
The Earth's axis is tilted 23.5 degrees as it travels around the sun. For half the year the northern half (or hemisphere) of the Earth is tilted toward the sun, for the rest of the year the southern hemisphere faces the sun. The part of the earth tilted toward the sun gets more direct sunlight, has longer days, warms up and has spring and summer. Meanwhile, the other hemisphere, tilted away, gets less sunlight and cools down for fall and winter.
The winter solstice is the precise time of the year when the Northern Hemisphere is tilted the farthest away from the sun. It also marks the time when winter officially begins. Of course, this is also the time the Southern Hemisphere is tilted most directly toward the sun, marking the beginning of their summer.
This year the winter solstice is at 1:27 p.m. MST on Tuesday, Dec. 21. From then until the summer solstice next June 21 the Northern Hemisphere will slowly increase its tilt toward the sun, days will get longer and temperatures will start to warm.