Snowpack in the Greater Yellowstone Ecosystem
In the Greater Yellowstone Ecosystem, the snowpack acts as a vital water source, gradually releasing its stored water throughout spring and summer. Snowfall varies significantly across the region, from approximately 90 inches in Jackson to almost 500 inches on the high peaks of the Tetons. To monitor this crucial resource, scientists rely on SNOTEL (SNOwpack TELemetry) sites equipped with sensors that measure snow depth, snow water equivalent, temperature, and other meteorological data. These stations, featuring snow pillows to measure snow weight and towers with instruments for measuring snow depth and air temperature, provide essential data for water supply forecasting, resource management, and climate research (Mountain Journal). This information is crucial for understanding how snowpack influences the delicate balance of the ecosystem and impacts the lives of wildlife within it.
The Science of Snowflake Formation
Have you ever stopped to wonder how snow forms or what makes each snowflake unique? At Wildlife Expeditions, we’re fueled by scientific curiosity and love to share our knowledge with you! Snowflakes are a marvel of nature, each a single ice crystal with a fascinating story to tell. As Wired.com explains, snow forms when billions of microscopic water molecules in the gas form freeze together and fall to the Earth. These crystals can only form when it’s cold enough to prevent the gaseous water molecules from condensing and forming rain or sleet. According to SnowCrystals.com, each snowflake is a unique hexagonal masterpiece. Water vapor in the air transforms directly into ice, bypassing the liquid state, and as this ice crystal grows, its intricate patterns emerge.
The magic of snowflake shapes lies in the delicate balance of temperature and humidity. SnowCrystals.com explains that thin plate-like crystals form at around -2°C (28°F), while slender columns appear at colder temperatures near -6°C (21°F). As temperatures plummet further, large, thin plates dominate, with the possibility of both plates and columns at even lower temperatures. Simpler snowflake shapes emerge in drier conditions where growth is slower, while branched crystals with complex structures thrive in high humidity where growth is rapid. The adage “no two snowflakes are alike” holds true thanks to the wonders of snow science! As each snowflake descends through the clouds, it encounters ever-changing temperatures and humidity. These variations cause slight differences in how each snowflake’s arms grow. The final shape is determined by the unique path each snowflake takes through the cloud layer. Since no two snowflakes follow the exact same path, their appearances are beautifully individual.
Yellowstone’s Hidden Subnivean World
The Greater Yellowstone Ecosystem transforms dramatically in winter, with snow blanketing the landscape. While large mammals like elk and bison adapt through migration or thick winter coats, a hidden world thrives beneath the snowpack. This subnivean, or ‘under the snow’ zone, provides a unique and vital winter refuge for a surprising diversity of life. Imagine a world where temperatures remain relatively stable around 32 degrees Fahrenheit, shielded from the bitter cold and wind above. This insulated environment supports a complex community, from microscopic microbes and fungi to small mammals like voles and shrews. These creatures navigate a network of tunnels, foraging for food, seeking shelter, and playing a crucial role in the ecosystem.
However, the integrity of this subnivean world is intricately linked to the characteristics of the snowpack itself. Yellowstone Forever explains that the relationship between snow thickness and density determines the snow’s ability to insulate. Deeper, lighter snow (with more air space between the snow crystals), similar to a cozy down sleeping bag, creates a more effective barrier against the cold, maintaining stable conditions for the life beneath. Changes in snowpack can disrupt the delicate balance, impacting not only the subnivean inhabitants but also the predators that rely on these creatures for food later in the year. “For species like pika—who may not be able to migrate or hibernate—changes in the subnivium can be catastrophic, particularly at the edge of their range where the snow is changing most rapidly”. (Yellowstone Forever)
A Changing Environment
Climate change is dramatically altering the snowpack within the Greater Yellowstone Ecosystem (GYE). Temperatures in the region have risen by an average of 0.31°F per decade, a warming trend that is expected to continue. A critical consequence of this warming is a significant decline in spring and summer snowpack. This reduction threatens the water supply for millions of people across the western U.S., as the GYE is the headwaters for major rivers like the Yellowstone, Snake, and Green. Furthermore, diminishing snow cover creates a dangerous feedback loop. Snow reflects sunlight, helping to cool the Earth. However, as snowpack declines, more sunlight is absorbed by the ground, further increasing temperatures and accelerating snowmelt. This cycle exacerbates climate change within the GYE. (National Park Service).
The Greater Yellowstone Ecosystem is a winter wonderland where snow, wildlife, and water resources intricately intertwine. From the delicate beauty of snowflakes to the hidden life thriving beneath the snowpack, every element plays a crucial role. Understanding the importance of snowpack and the threats it faces is essential for protecting this irreplaceable ecosystem. Experience the magic firsthand on a snowcoach tour with Wildlife Expeditions. While the subnivean world remains hidden, you’ll encounter thrilling above-snow wildlife sightings, witness Yellowstone’s geothermal wonders from a unique perspective, and learn from our passionate guides. If this blog has ignited your curiosity about stellar dendrites, snowpack, and the GYE’s winter secrets, join us on a tour!
Sources:
https://www.nps.gov/yell/learn/nature/changes-in-yellowstone-climate.htm
https://www.yellowstone.org/what-lies-beneath-the-snow/
https://www.tetonconservation.org/snowpack-information
https://mountainjournal.org/eric-larson-the-man-behind-the-snowpack
https://www.snowcrystals.com/morphology/morphology.html
https://www.wired.com/story/the-science-behind-why-no-two-snowflakes-are-alike/