by Teri Franzen
Snow and ice provide ornamentation to the world that is new and unique with each changing weather pattern. There is something magical about that pristine blanket of white draped over the landscape. Everything looks clean and the crisp air smells fresh. Icicles fringing a lake or river create a lacy delicate beauty that glistens and glows.
All of this decoration isn't just for show. Both snow and ice are formed from the same substance: water. Ice is water in its solid form and snow is made up of ice crystals. Tasteless, odorless and colorless, water is the most critical substance on earth. The human body is about 60% water. Among its countless uses, we drink water, cook with it, bathe with it, clean with it, use it to water plants and crops, freeze it to cool drinks and boil it to sanitize instruments. Water in motion as waterfalls and mills produce power. Water truly is life.
This article celebrates the natural beauty of water in its solid form and highlights the importance of that solid as illustrated by the wonderful images provided by local photographers.
Ice
Water molecules are formed by two hydrogen atoms bonded to one oxygen atom. These molecules form bonds with other water molecules due to a process called “hydrogen bonding”. In temperatures above freezing, the bonds form and break at a high frequency. As water freezes, the kinetic energy of the water molecules falls below the energy of the hydrogen bonds, causing the them to form more frequently than they break. These bonded molecules produce the hexagonal shapes we see in ice crystals and are more spread out. The resulting ice is less dense than liquid water. This is what causes ice to float at the top of a surface and is critically important to the aquatic organisms that thrive in our lakes and rivers. Surface ice protects its inhabitants from the cold winter air. If water froze from the bottom upward its resident organisms would freeze and most would not survive the winter.
As surface ice melts in the hot sun, then refreezes, it takes on patterns from the movement of the water beneath the surface. This is illustrated in this image photographed by Sarah Darling-Jones. Sarah wrote, "This was taken at Dorchester Park of Whitney Point Lake during a winter thaw. The ice was melting and the sun was shining off of the crystal water hidden underneath the ice."
As temperatures drop, water that has seeped into soil can freeze. As the moisture freezes the molecules expand, creating crystals that emerge from the surface as is seen in Christine Chady's image below. If this occurs rapidly it has been known to produce seismic activity resulting from mini explosions underground. This is called a cryoseism or frost quake.
As ice melts, gravity pulls the heavier water droplets downward. Encountering the cold air the exposed water drops then freeze. This can form intriguing shapes like this fun image of "Winter Bats" photographed by Christine Chady.
Photography Tip: In her image, Christine has focused on the icicles and used a slow shutterspeed technique, at 1/20, seconds which captures motion blur of the water. This softens the background and isolates the foreground "bats" from the rushing water.
Snow
A snowflake forms when the air temperature approaches freezing at 32° fahrenheit (0° celsius). Water vapor in clouds attach to dust particles which turn to ice, crystalize and fall to the ground. The crystal forms as a hexagon. Branches spread from the corners and, based on temperature and the amount of moisture in the atmosphere, tendrils may form. These tendrils will continue to form uniquely in reaction to temperature and humidity encountered by each individual arm, which is why it is said that no two snowflakes are exactly alike. For reference, here is a closer look at a snowflake photographed by Teri Franzen showing three visible main tendrils, each uniquely formed.
As snowflakes fall, they gather on surfaces and begin to form snowpack. In much of the eastern US that snowpack is temporary and rarely collects for longer than a few weeks during winter. Throughout those bitter cold months, snow acts as an insulator, protecting planted bulbs and root systems from freezing air. Many animals burrow into snowbanks to find insulation from the cold. It also provides a source of hydration for wintering wildlife that eat snow when there is no available water. During the springtime, snow melts to provide irrigation for plants and crops.
In higher altitudes and colder climates, snowpack gathers over many years. As it melts, the snow provides a primary source for streams and rivers and ultimately produces household water. For many centuries, that snow has replenished, therefore maintaining a sustainable level. However, in recent decades, winters have become shorter and snowfall less abundant. This result of climate change has begun to wreak havoc worldwide, contributing to drought and increased threat of wildfires, among other concerns. There are many great resources for learning more about the diminishing snowpack, a few of which I have linked below.
In addition to its practical purposes, fresh snowfall can make ordinary winter scenes look magical as is illustrated by Kelly Frederick Sweet's image of an apple wearing a hat woven from fresh snowflakes.
As with ice, snow melts as it warms and the molecules shrink. The resulting water sinks or drops to the ground. Gina Vaughan's image below shows the partially formed crystals as they melt and cling to the surface.
In Kelly Frederick Sweet's image "Snowcapped", you can see the moisture that has been absorbed below the snow which appears to have retracted. Icicles has begun to develop on the fringe as the water hits the cold air and again freezes.
In Stan Edwards' whimsical image of snow-topped thistles, the snow has balanced at the very tips of these seedheads. In this case, the vegetation has likely retained a small amount of heat, causing the snow or ice to melt away from the surface.
Resource Links
Water
Water in motion (blog)
Water is life - an ode to the Rio Mamoni (video)
Snow
Ice
Snowpack
Articles:
https://phys.org/news/2014-04-snowpack-ecosystem.html
https://en.wikipedia.org/wiki/Snowpack
Videos:
The Snow Guardian - The story of Billy Barr the citizen scientist who measured snow daily for more than 40 years from his remote location of Gothic, Colorado
The End of Snow - A further expansion on the loss of snowpack and its effects on the ecosystem, includes a form of the above video.
About the Author
An active member of the Waterman Center board of directors, Teri Franzen is a professional wildlife photographer, videographer, writer, naturalist and conservationist working to promote natural history awareness through photography education. With a strong emphasis on ethics, Teri is passionate about observing and photographing wildlife on its terms, wild, unaltered and undisturbed.