Why icicles appear
Icicles formed at a time when the difference of day and night temperatures becomes significant.In March days already noticeable sun warms, snow on the roof melts.Water flows down the slope and at the edge of the droplet is formed.If it is large and heavy, it is likely to soon fall.A drop of less than 5 mm in diameter is on the edge of the roof.
The evening, the air temperature is lowered to zero or below, the water freezes.The drop does not have time off and freezes in a position in which it is caught cold.In the morning the temperature rises again.Frozen drop melts more slowly than the snow in the middle of the roof, so that it has time to join another small droplet, and maybe mor
e than one.There is a small icicle, which is starting to grow.
Sometimes, icicles appear in the winter, when there is no thaw.This happens because the roof can be warmed not only outside, but inside - steam heating systems and furnaces.Roof warms snow melts, water runs off the edges and freezes because the temperature at the eaves is much lower than in the central regions of the roof.Ice forms, which does not allow water to drain.The worse the insulation, the more water flows to the edges, and the larger will be the icicles.
Large icicles are a danger to pedestrians and vehicles, so it is very important to insulate the roof.
Large and small icicles
long been observed that in the coastal countries of the icicles almost not formed.There is nothing surprising in this.For example, in the Baltic countries have long built houses with sharp high tiled roofs.Snow they are not delayed, and therefore does not melt, and does not flow streams.If the slope angle is less than 40 °, icicles formed much more rapidly.Playing the role and the material from which made the roof.The smooth surface of the high roof prevents snow linger.
One means of combating large icicles - timely snow removal from roofs.
After considering several icicles spring, you can be sure that some of them are perfectly smooth, while others have grooves.This is most clearly evident in the large icicles.Icicles form depends on the composition of water.Distilled water gives an absolutely smooth surface, since it contains no salts.The higher the salt concentration, the more pronounced will be the groove, but retains icicle conical shape.However, there comes a time when the salt reaches a certain limit, and then the icicle can buy the most bizarre form.On this basis we can determine, for instance, how much snow is contaminated with salts in your city.