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Basic Structure and Formation of Snowflakes
Aggregation of Crystals
Snowflakes Stem from Ice Crystals
snowflakes, also known as snow crystals, are arrangements of tiny ice crystals that grow from water vapor. To form snowflakes, ice crystals freeze around tiny dust particles permeating the atmosphere, and attach to other ice crystals as they descend to the ground, giving form to snowflakes. The shape that a snowflake takes is determined by weather conditions, including temperature, wind and water vapor in the atmosphere, as well as the amount of time it takes for the snowflake to reach the ground.
Snowflake is a broader term to designate a collection of individual ice crystals. Normally, ice crystals cluster together during a snowstorm, creating complex symmetrical structures, resulting in snowflakes. Each ice crystal, during formation, acquires a singular and well-formed structure. The best known ice crystal structures include the Star Crystal, Columns, Capped Columns, plates, Needles, spatial Dendrites and irregular forms. The structural arrangement of ice crystals derives from the molecular arrangement of water and hydrogen atoms.
Ice Crystal Growth Depends on Temperature and Humidity
The formation of snowflakes begins in the clouds with the condesation of water vapor (nucleation) around small particles of dust to form ice crystals. At temperatures below the freezing point 0° C (32° F), water vapor begins to freeze into crystal nuclei. As the crystal begins to grow, it is carried high in the cloud to colder temperatures, acquiring a hexagonal prism form. diffusion causes branches to grow out from the corners of the growing crystal. The snowflake continues rising up to cooler temperatures, attracting more crystals. When the snowflake is heavy enough, it begins to fall to the ground.
Snow crystals growth depends on temperature and water vapor supersaturation; however, it is temperature which will determine wether they will grow into plates or columns. At -2° C (31.8° F), snow crystals are predominantly plates, changing to needles and columns at -5° C (28.8° F). At -15° C (18.8° F), they´re plates; however, at 30° C (3.8° F), they´re both columns and plates. At lower temperatures, columns predominate.
Ice crystals organize themselves symmetrically, in a similar way in which water molecules do. Water molecules form hydrogen bonds with one another in the solid state (ice and snow). these bonds lead to the hexagonal six-sided shape characteristic of snowflakes. During crystallization, water molecules arrange together to give form to a crystalline lattice. this hexagonal crystalline symmetry is what in the end will determine the form of a snowflake.
Uniqueness of Ice Crystals
Each snowflake is characterized by being unique among other snowflakes. Throughout their displacement from the clouds to the surface of the ground, each snowflakes follows different paths, encountering on their way a variety of weather conditions, such as temperature, wind, and humidity which is what will determine the particular structural characteristics of a snowflake. Moreover; the time it takes each snowflake to get to the ground plays an important factor in their molecular arrangements. If two snowflakes were to acquire the same structure, they would have to go through analogous paths and under similar atmospheric conditions.
Snowflakes Used as Symbols
The shape of snowflakes has given rise to various uses in popular culture, for instance, the snowflake is a symbol during the Christmas season, especially in Europe and the United States. It is in this season that people tend to make paper snowflakes to be used as Christmas decorations.
During the 2002 Winter Olympic Games in Salth Lake City Utah, the organizers chose a snowflake as the representative symbol of the games.
In 1999, rubber manufactures of both Canada and the United States agreed on the use of a snowflake on the tire sidewall to distinguish tires with a superior level of snow traction.