Vail Daily column: The shortest day of the year
The winter solstice is the shortest day of the year. Sunday, Colorado will experience more than 14 hours of darkness.
The literal etymology of the term “solstice” means something akin to “standing sun.” The point on Earth below where the sun’s light is most intense can be considered where it “stands.” Sun rays are most intense in tropical latitudes near the equator, and far less intense in the more northern latitudes.
From December to March, when it is snowy, cold, and dark here in the northern hemisphere, it is because the daytime sun stands above southern Brazil, South Africa, and Australia. The opposite is the case in June, during Colorado’s summer solstice. Then, the sun stands above Mexico, India, and the Sahara Desert.
Although the most intense rays are closer in summer, the sun never stands directly above Colorado. Differences in where sunlight strikes Earth result in seasonal temperature changes.
The 21st of December is also the first day of winter in the United States. Because it is the shortest day of the year, each following day has more and more sunlight. And while it might seem like more light would mean warmer days, this isn’t the case.
In the Colorado mountains, the snowiest month of the year is March. However, on Vail Mountain the snowiest month each year, most years, is April (http://www.cbrfc.noaa.gov/station/sweplot/sweplot.cgi?vlmc2) (according to the National Oceanic and Atmospheric Administration, Oct. 2). The simplest explanation for increasing snowfall late in the winter and early in the spring is that our air is colder. The colder air has to do with the time of year and the low intensity of sunlight.
The months following December are colder because there are still more hours of darkness in each day than light. Here the mountains cast shadows which also increase the amount of shade each day. Day after day, the air continues to cool until the vernal equinox in March, when the hours of day-light and nighttime-shadow, at least on level ground, are again equal. In spring and summer, our atmosphere warms due to surplus light and a deficit of shadow. Come September, the autumnal equinox and darker days are harbingers of another winter solstice.
Human awareness of the winter solstice dates back to times when, after the sun set, our ancestors watched campfires and the night sky. Watching the sky was important to predict the seasons and the weather, and stars were also important bearings for navigation before maps were invented.
For instance, have you ever noticed that the constellation Orion is only visible in the winter? If not, ask a parent or a friend for help to locate this winter visitor on a dark night, before it disappears with the longer summer days.
To our ancestors, who were more attuned to the seasonal changes in daylight, the shadows and chills of the winter solstice symbolized death. During winter time, resources such as food, water, and shelter are scarcer. Many tribes and communities would gather for survival. However, rather than letting dark days dictate the mood, this shortest day is commonly celebrated as a sort of finish line before the summer warmth to come.
A winter solstice tradition my parents started is a poetry slam where family and friends turn on the lights, sing together, and stay up late. In this way we celebrate the approaching dawn of spring and summer. Other celebrations around the 21st of December are similarly meant to bring communities together during a dark part of the calendar year. Take time this year to observe the winter solstice in whatever way feels right to you, because it only happens once a year.
Warm the cold. Light the night. Come together.
Sage Smith is a naturalist intern with Walking Mountains Science Center in Avon. He shakes like a mountain, screams like a songbird, takes and gives like water’s tentacles, and every time he breathes, wind blows.