Snow Facts: 11-15 | Snowflake explained
11. It doesn’t however necessarily means that the snowflakes will grow symmetrically. Conditions like micro-environment in which snowflakes are formed and the mechanism in which the crystals grow often determine how fast a surface of a crystal will grow.
12. A snowflake’s shape is often determined by the humidity and temperature in which it is formed. Different snowflake shapes that are observed in different temperature are mentioned in the table below:
|Air temperature||Snowflake shape|
|-3°C||Flat and thin crystals known as Planar Crystals|
|-8°C||Needles, Prisms or Hollow Columns|
|-22°C||Plate-like but with dendritic or branched features|
13. Also remember that the saturation degree will determine whether the snowflakes will become columnar or plate-like.
14. In total, 80 different shapes of snowflakes have been identified so far. All these different shapes are segregated into 8 major categories which are:
- Needle crystals
- Columnar crystals
- Plate crystals
- Combination of plate and columnar crystals
- Columnar crystals having extended side panes
- Rimed crystal
- Germ of snow crystal
- Irregular snow crystal
15. During snowfall, large enough snow crystals can fall individually as single ice crystals. However, several ice crystals can actually cluster or club together to become heavy enough to fall. So, snowflakes can be singular or clusters of ice crystals.
Snow Facts: 16-20 | Hoarfrost explained
16. Hoarfrost is something different. It is a type of snow in which ice crystals get deposited on those surfaces that have temperature lower than surrounding air’s frost point.
17. In scenarios like this, moisture will convert directly into solid from the vapor state by bypassing the liquid phase.
18. In hoarfrost, ice crystals are generally interlocking and they will form on objects that have small diameter.
19. Hoarfrost is usually found on leaf edges, plant stems, tree branches, poles, wires etc. One of the most important criteria for hoarfrost formation is that the surface on which it will be formed should be exposed to air freely.
20. Hoarfrost is often called by different names depending on where it is formed. The names are given in the table below:
|Air hoar||Hoarfrost deposits on surfaces like wires, plant stems, tree branches etc.|
|Surface hoar||These are ice crystals with appearance of ferns and are deposited on surfaces that are already frozen or on ice or snow.|
|Depth hoar||These are faceted crystals that gradually grew large inside cavities present beneath dry snow surfaces or surface of banks.|
|Crevasse hoar||These are crystals that are formed in crevasses of glaciers where calm weather conditions allow water vapor accumulation.|