Explanation text

Explanation text:

SNOW

Snow, an amazing natural phenomenon:my love as warm Snow

Febdian Rusydi (RijksuniversiteitGroningen)

At this time in Europe and the northern regions of the Earth the middle of winter.One of the interesting phenomenon of the moment winter is snow. Be unique becausethe ice crystals are soft and white as cottonit just comes naturally in the land of the four seasons or in places that are very high as Jayawijaya mountain peaks on Papuan.Why snow naturally could not present intropical regions such as our country?

The process of the formation of snow

To answer that, we can start the process ofoccurrence of snow. Starting from water vapor that gather in Earth’s atmosphere, the water vapor cools to the point ofcondensation (i.e. the temperature at which the gas turns into liquid or solidforms), then rotate to form clouds. At the beginning of the formation of clouds, its mass is much smaller than the mass of the air so that the clouds float in the air just like wooden beams which floats on the surface of the water. However, after the steam collection continues to grow and merge into the cloud, its mass alsoincreases, resulting in a when air was notable to hold him again. The clouds broke and the water particles ever fallen to Earth.

Water particles that fall it was pure water(not doped by other particles). Pure waterdoes not freeze in temperatures of 0degrees Celsius, because at thetemperature of liquid phase changes tosolid. To make pure water freezingtemperature required is lower than 0degrees Celsius. This also happens when we menjerang water, water evaporateswhen the temperature above 100 degrees Celsius because at 100 degrees Celsius is the change of phase from liquid to vapor.To speed up the change of the phase of a substance, usually added specialsubstances, for example, salt is used toaccelerate the phase of melting ice towater.

Usually the air temperature just below theclouds is below 0 degrees Celsius (air temperature depending on the heightabove sea level). But, the low temperaturealone is not enough to create snow. Whenparticles of such pure water in contact withair, then the pure water of distortion byother particles. There are certain particlesthat function accelerates the freezingphase, so that pure water is rapidly becoming the ice crystals.

Pollutant particles involved in this process is called nukleator, in addition to functioning as the freezing phaseAccelerator, also the adhesive antaruapwater. So the water particles (which are not pure anymore) joined together with other water particles to form larger crystals.

If the air temperature is not to melt the ice crystals, ice crystals falling to the ground.And here’s the snow! If not, the ice crystalsmelt and get to the soil in the form of rainwater.

In many cases in the world, the process ofthe decline of the rain always starts with the snow some when she fell from the clouds, but then melted away whencrossing the hot air. Sometimes, if the temperature is very low, the ice crystals canform small balls of ice and sleet. Bandung city included relatively frequentlyexperience hail. So, this is why the snowwas very hard down naturally in thetropical regions that have relatively highair temperatures than areas that are currently experiencing winter.

The unique structure of the snow

Snow Crystal has a unique structure, no snow crystals that have the same shape in this world (see figure URSnowflakesWilsonBentley.jpg) is like a fingerprint. Imagine, the snow‘s beencoming down since the Earth was createdup to now, and none of the snow has the same crystal structure!

The uniqueness of the snow is white in colour. If it’s snowing, the expanse of the Earth as white, clean, and seemed to beglowing. This is due to the Crystal structureof the snow allows snow to reflect all the colors to all directions in the same amount, then came the white color. The same phenomenon can also be seen when we seewhite sand, salt chunk, chunks of sugar, mist, cloud, and white paint.

In addition, the decline in snow providewarmth. This can be understood from the concept of the effective temperature.Effective temperature is the temperaturefelt by our skin, is influenced by threephysical quantities: the measuredtemperature (by the thermometer), the speed of movement of the air, and the airhumidity. Effective temperature is typically used to determine the comfort zone. On the beach, the measured temperature can be high, but due to the high winds we still feel comfortable. By the time the snow fellheavy, humidity rises and this influenced the effective temperature so on onecondition we felt warm.