It originates in clouds when temperatures are below the freezing point 0 degrees Celsius, or 32 degrees Fahrenheit , when water vapor in the atmosphere condenses directly into ice without going through the liquid stage. Once an ice crystal has formed, it absorbs and freezes additional water vapor from the surrounding air, growing into a snow crystal or snow pellet, which then falls to Earth. Graupel is composed of small pellets of snow. Unlike the hard balls of ice that form hail, graupel tends to be smaller, with a soft and crumbly texture.
One form of precipitation, hail , while frozen, is not considered snow. Hail tends to be larger than sleet, and is usually generated during thunderstorms, which happen more often in spring and summer than in winter. I am involved in a research project investigating how the changes in temperature and snow cover duration are likely to affect the extinction risk for northern flora. The results so far show that many species may actually benefit from a warmer climate if snow conditions remain as they are.
But since the warming will most likely reduce the amount snow, it may wipe out a large part of the flora that are typical to Arctic mountains, such as snow buttercup and mountain brook saxifraga. Although the significance of snow is widely recognized, winter conditions are often ignored in studies of the Arctic areas. This may seem surprising, but the reason for this shortcoming is practical rather than ideological: gathering data on winter conditions from remote Arctic areas is extremely challenging.
Polar nights and freezing temperatures do not tempt researchers to step outside, and the harsh conditions are a true trial for the research equipment. We have tackled these practical difficulties by using satellite imagery and hardy miniature logging devices. Satellites have provided us with detailed information about Arctic snow conditions since the s. What researchers need most is patience to process the massive datasets and computers with plenty of power and memory.
Small temperature loggers have proven themselves weather-proof in the harsh Arctic winter conditions. As long as reindeer and lemmings leave the loggers untouched, they offer in-situ data to validate the satellite record. Thanks to remote sensing and species distribution models, we know that winter and snow are hugely significant for the future of northern nature and organisms.
Many Arctic and mountain plants grow and flower during very short summers. If the snow cover duration shortens and summers lengthen, the more southern species will benefit and could compete with Arctic species for survival, leading to the extinction of some Arctic species. Mountain avens and glacier buttercups, two iconic Arctic flowering plants, require very different snow conditions, but both are very much affected by these changing conditions.
The construction of dams and the management of water flow by humans can be very helpful for human activities, but it can also have negative impacts on ecosystems. Learn more about the importance of snow in supplying water for agriculture , electricity , human consumption , and natural ecosystems. Scientists have observed changes in how much of the planet is covered by snow each year, the total amount of snow that it receives, the timing of spring snowmelt, and how much winter precipitation falls as rain versus snow in some areas Sturm, et al.
Some scientists study snow by observing and recording the depth, density, and other characteristics of snow on the ground by digging snow pits. Automated weather stations also provide information about snow. Because snow covers such a large area and varies greatly from place to place and year to year, the study of snow is often conducted by remote sensing, which collects data from a distance using satellites or aircraft. Ground-based study of snow is important for understanding local characteristics of snow such as temperature, grain size, layering, and density and for detecting variation in snow conditions from place to place and over time.
Skip to content Home Importance of Snow. Snow has a high albedo value, meaning that it reflects more solar radiation than it absorbs. In many areas, melting snow in the mountains is a critical source of water for agriculture, electricity generation, and human and industrial use.
The Hungry Horse Dam in Montana generates electricity, provides flood control, and stores water for use by power plants downstream on the Columbia River. Bureau of Reclamation Photo Public Domain.
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