The question of how snow forms often intrigues many. The charm of snowflakes gently descending and the beauty of a whitened landscape rarely leave one indifferent. There’s something pure and peaceful about this natural phenomenon. But first and foremost, what exactly is snow? Today, we want to delve into this extraordinary atmospheric manifestation that frequently visits our territories during the winter months.
Besides satisfying our curiosity about the formation of this atmospheric precipitation and the weather conditions that favor it, let’s also explore the significant agronomic benefits that a heavy snowfall brings to the land.
Getting to Know Snow Better
Snow is a type of atmospheric precipitation that reaches the ground in the form of crystalline ice water. It consists of thousands of tiny ice crystals, each with a unique geometric shape. Randomly aggregating together, these crystals form what we commonly refer to as snowflakes.
The granular consistency is due to its composition of very small raw particles, and the ice crystals have an open molecular structure. This gives the snow that falls on the ground its characteristic softness. Children love this feature, as they eagerly await the opportunity to play and frolic on the white blanket with their sleds and snowsuits. However, it can be challenging for drivers who find themselves needing to use tire chains and snow tires to cope with the snowy roads.
Another unique aspect of falling snow is that no two snowflakes are ever identical. As they journey from the sky to the ground, each ice crystal undergoes countless interactions with the atmosphere, resulting in infinite variations.
How Snow Forms
Snow formations occur in the upper atmosphere. Water vapor with temperatures below 5 °C freezes and solidifies around ice nuclei. This transition changes it from a gaseous state to a solid state, forming snowflakes. As soon as their weight overcomes the buoyancy of the air, these snowflakes begin to fall to the ground. That’s how snow forms.
The snowflakes manage to reach the ground and create the snow cover when the ground’s temperature is below 2 °C. Additionally, it’s crucial to maintain a temperature near the freezing point at intermediate atmospheric levels. This prevents the snow from turning into sleet or rain.
Types of Snow
We have seen how snow forms, but from experience, we know that not all snowfalls are the same. There are many types of snow precipitation: large or small flakes, round snow, snow mixed with rain, hail, graupel, and snow showers. The type of precipitation that will occur in our area depends on various factors, primarily the type of disturbance generating it.
The Benefits Snow Brings to the Soil
An ancient proverb from the farming tradition says, “Bread under the snow, hunger under the water”. This indicates that when snow falls and remains on the ground for some time, it brings benefits and fertility.
Water Reserve
Snowfall is a formidable and essential water reserve for the soil. As it gradually melts, it allows the soil to absorb the water completely. The water absorption is significantly higher compared to what would happen if the same amount of water arrived as rain.
This direct benefit is very evident on sloping terrains, where water generally washes away. On flat grounds, it allows deep water percolation, preventing waterlogging, which heavy rainfall often causes.
In agriculture, water requirements are substantial. Timely snowfall is like manna from heaven, at least as our farming ancestors viewed it.
Hydrogeological Risk Mitigation
As if that weren’t enough, this atmospheric phenomenon protects the territory from hydrogeological risks. This is because, by being entirely absorbed by the soil, it doesn’t end up in streams and doesn’t cause the damages of intense rains.
So, don’t worry if your garden is covered with a beautiful white blanket when the snow arrives, especially if you live in areas where such precipitation is now scarce and sporadic. In spring, you’ll have a great water reserve that your future crops will appreciate.
Frost Protection
Lastly, it’s worth mentioning an unexpected and particular function. Not everyone knows that the snowy blanket can protect our crops from frost. Vegetables like broad beans, peas, garlic, fennel, turnip greens, spinach, chard, benefit from and are protected by the snow. This is because the snowflakes consist of one part water and nine parts air trapped inside. The air acts as a thermal insulator and retains the heat coming from the ground. This phenomenon, in turn, shields the plants from temperature fluctuations and intense cold.
Now that we’ve seen how snow forms and the benefits it brings to the soil, remember: frost is the true enemy of our crops, not snow!
Further Reading
- American Geophysical Union – “Snow as an Important Natural Reservoir for Runoff and Soil Moisture in Northeast China” – This study discusses the role of snow as a natural reservoir for runoff and soil moisture in Northeast China. It highlights the importance of snow in maintaining soil moisture during dry seasons.
- National Snow and Ice Data Center – “Science of Snow” – This article provides an in-depth explanation of the science behind snow, including how it forms and its impact on the environment.
- ScienceDirect – “Impact of snow cover on soil temperature and its simulation in a boreal aspen forest” – This research paper discusses the impact of snow cover on soil temperature in a boreal aspen forest. It emphasizes the role of snow as an insulator that can affect root systems of trees and shrubs.
- University of Nebraska-Lincoln – “The Benefits of Snow” – This article discusses the benefits of snow for yard and garden plantings. It highlights how snow acts as an excellent insulator of the soil, protecting perennials, bulbs, ground covers, and strawberry plantings from alternating freezing and thawing cycles.
