How rain, snow, hail, dew and frost are formed: physics of processes. Atmospheric precipitation: what is it and how is it formed
How dew, frost, rain and snow are formed in nature.(abstract)
The formation of dew, frost, rain and snow is an interesting geographical and physical phenomenon, which is explained differently from each point of view. But in order to better understand what happens in nature during these phenomena, it is better to turn to the laws and formulas of physics.
There is always water vapor in the atmosphere. This occurs due to the continuous evaporation of water from the surface of oceans, seas, rivers and lakes. Air humidity varies in different places due to differences in climate and distribution inland waters on the surface of the water. For example, above the surface of the equatorial seas the humidity is very high, and above the deserts it is very low. Although there is little water vapor in the air, it is this vapor that determines weather. Except evaporation important role plays a role in the condensation process. In nature, condensation of water vapor occurs in different ways: dew or frost can form, rain or snow can fall.
Consider the formation of dew. It can only be seen in the early morning. On a hot summer day, water evaporates from the surface of lakes, rivers, reservoirs and plants. At night, when the temperature drops and can reach such a value that water vapor becomes saturated. This point is called the dew point. At that time saturated steam condenses and settles on the surface of the earth and on plant leaves. Therefore, we can see dew only in the early morning, when it has not yet evaporated under the influence of sun rays.
The formation of frost is similar to the formation of dew, but the only difference is that dew appears in the hot season, and frost appears in the cold season, that is, in winter or late autumn. During a thaw, air humidity rises. If after this the temperature drops below zero Celsius, the condensed water will freeze and settle on the surface of the earth and plants. Frost, like dew, can only be observed in the morning due to the fact that it is usually colder at night than during the day.
Precipitation plays an important role in the water cycle in nature and in the life of animals and plants. Usually they are formed like this. Water evaporates in large quantities from the surface of oceans, seas, rivers and lakes, and steam rises several kilometers upward. The temperature there is quite low, and the steam condenses and turns into tiny drops that seem to float in the atmosphere. A huge number of these droplets form a cloud. Under the influence of air currents they are transported over vast distances, sometimes covering several thousand kilometers. As they move, they collide with each other, turning into larger drops. When they grow enough, they will fall to the ground as rain.
Snow forms in a similar way, but in cold weather, when the temperature at the altitude where steam condenses is less than zero. In this case, not water drops are formed, but ice crystals.
How snow is formed
Everyone perceives snow as simple precipitation. In fact, these are tiny ice crystals that are formed from water vapor. We are used to seeing snow in the form of snowflakes or groups of them (flakes). The mechanism of its formation is quite simple: drops of water that are concentrated in clouds freeze at low temperatures. As a result, small ice crystals form, which, as they fall, increase in mass and are susceptible to the influence of wind. This explains their shape.
The shape of one crystal has six ends. It is worth noting that the angles between each end are always correct and equal to 60 or 120 degrees. This is facilitated by the design of the water molecule. The variety of snowflakes is simply amazing. It is impossible to find two identical snowflakes in the world. But the crunching sound that snow makes when compressed occurs due to their fracture, or rather the crystals from which they are formed.
How frost forms
This type of precipitation is formed due to the process of desublimation, that is, the transition of water vapor (gaseous substance) into a solid state. Contains steam in atmospheric air. Frost settles on the surface of plants, soil, objects located on the ground, as well as on the snow cover. The process itself is explained quite simply: as a result of thaws, evaporation occurs, which, when reduced, atmospheric temperatures freezes evenly. At the same time, on many surfaces, beautiful patterns and drawings.
For frost, the most suitable location is a rough surface that has low heat conductivity (for example, open soil or a wooden bench). It usually forms on windless nights. If the weather is too windy, then frost formation will not occur, since a powerful wind flow prevents this process. But a light breeze, on the contrary, creates excellent conditions for the formation of frost. It is thanks to the active movement air masses, moisture that evaporates comes into contact with other surfaces.
How dew is formed
See this a natural phenomenon possible early in the morning. Best observed at first light. In hot weather it evaporates enough a large number of moisture that remains in humidified air. Night temperatures help collect moisture into condensation, which then sinks to the surface. From the very morning this moisture can be noticed everywhere.
Dew appears only when warm temperatures. Different regions have different intensity of dew formation. Most often it can be observed in places with a tropical climate.
How is rain formed?
In fact, it is quite simple to explain the formation of rain. When, heated by high temperatures, air currents carry water vapor upward to the clouds, low temperatures, located there, turn the steam into ice crystals. Due to the formation of crystals, their weight increases significantly, which leads to their falling to the ground. During flight, the frozen crystals are exposed to warm air currents, which contribute to their transition from solid to liquid. This is how drops of water reach the surface of the earth. This precipitation is called rain.
When exposed to air currents, clouds are transported over considerable distances, sometimes covering thousands of kilometers. In the process of colliding with each other, they unite. And when their mass becomes higher, the drops fall to the ground.
The interesting thing is that they have an identical shape. Only the size varies; it can reach 6 mm in diameter. Such drops are called drizzle. When colliding with earth's surface large drops break up, forming many small ones. Intense rainfall can be observed in the corners of the planet where evaporation occurs most. In hot climates, evaporation occurs faster, the surface heats up, which contributes to the transformation of steam into rain.
MUNICIPAL EDUCATIONAL INSTITUTION
BASIC EDUCATIONAL SCHOOL in the village of SEVERNY
REPORT ON THE TOPIC:
“How dew, frost, rain and snow are formed in nature”
Prepared the report
8th grade student
Rubtsov Dima
Physics teacher
Gusarova Larisa Alexandrovna
2012
How dew, frost, rain and snow are formed in nature.
The formation of dew, frost, rain and snow is an interesting geographical and physical phenomenon that can be explained differently from each point of view. But in order to better understand what happens in nature during these phenomena, it is better to turn to the laws and formulas of physics. There is always water vapor in the atmosphere. This occurs due to the continuous evaporation of water from the surface of oceans, seas, rivers and lakes. Air humidity varies in different places due to differences in climate and the distribution of internal water on the surface of the water. For example, above the surface of the equatorial seas the humidity is very high, and above the deserts it is very low. Although there is little water vapor in the air, it is this vapor that determines weather conditions. In addition to evaporation, the condensation process plays an important role. In nature, condensation of water vapor occurs in different ways: dew or frost can form, rain or snow can fall.
Consider the formation of dew. It can only be seen in the early morning. On a hot summer day, water evaporates from the surface of lakes, rivers, reservoirs and plants. At night, when the temperature drops and can reach such a value that water vapor becomes saturated. This point is called the dew point. At this time, the saturated steam condenses and settles on the surface of the earth and on the leaves of plants. Therefore, we can see dew only in the early morning, when it has not yet evaporated under the influence of sunlight. The formation of frost is similar to the formation of dew, but the only difference is that dew appears in the hot season, and frost appears in the cold season, that is, in winter or late autumn. During a thaw, air humidity rises. If after this the temperature drops below zero Celsius, the condensed water will freeze and settle on the surface of the earth and plants. Frost, like dew, can only be observed in the morning due to the fact that it is usually colder at night than during the day.
Precipitation plays an important role in the water cycle in nature and in the life of animals and plants. Usually they are formed like this. Water evaporates in large quantities from the surface of oceans, seas, rivers and lakes, and steam rises several kilometers upward. The temperature there is quite low, and the steam condenses and turns into tiny drops that seem to float in the atmosphere. A huge number of these droplets form a cloud. Under the influence of air currents they are transported over vast distances, sometimes covering several thousand kilometers. As they move, they collide with each other, turning into larger drops. When they grow enough, they will fall to the ground as rain. Snow forms in a similar way, but in cold weather, when the temperature at the altitude where steam condenses is less than zero. In this case, not water drops are formed, but ice crystals.
How snow is formed
Everyone perceives snow as simple precipitation. In fact, these are tiny ice crystals that formed from water vapor. We are used to seeing snow in the form of snowflakes or groups of them (flakes). The mechanism of its formation is quite simple: drops of water that are concentrated in clouds freeze at low temperatures. As a result, small ice crystals form, which, as they fall, increase in mass and are susceptible to the influence of wind. This explains their shape.
The shape of one crystal has six ends. It is worth noting that the angles between each end are always correct and equal to 60 or 120 degrees. This is facilitated by the design of the water molecule. The variety of snowflakes is simply amazing. It is impossible to find two identical snowflakes in the world. But the crunching sound that snow makes when compressed occurs due to their fracture, or rather the crystals from which they are formed.
How frost forms
This type of precipitation is formed due to the process of desublimation, that is, the transition of water vapor (gaseous substance) into a solid state. Contains steam in atmospheric air. Frost settles on the surface of plants, soil, objects located on the ground, as well as on the snow cover. The process itself is explained quite simply: as a result of thaws, evaporation occurs, which evenly freezes as atmospheric temperatures decrease. At the same time, beautiful patterns and designs are formed on many surfaces.
For frost, the most suitable location is a rough surface that has low heat conductivity (for example, open soil or a wooden bench). It usually forms on windless nights. If the weather is too windy, then frost formation will not occur, since a powerful wind flow prevents this process. But a light breeze, on the contrary, creates excellent conditions for the formation of frost. It is thanks to the active movement of air masses that the moisture that evaporates comes into contact with other surfaces.
How dew is formed
You can see this natural phenomenon early in the morning. Best observed at first light. In hot weather, a fairly large amount of moisture evaporates, which remains in the humidified air. Night temperatures help collect moisture into condensation, which then sinks to the surface. From the very morning this moisture can be noticed everywhere.
Dew appears only at warm temperatures. Different regions have different intensity of dew formation. Most often it can be observed in places with a tropical climate.
How is rain formed?
In fact, it is quite simple to explain the formation of rain. When, heated by high temperatures, air currents carry water vapor upward to the clouds, the low temperatures found there turn the vapor into ice crystals. Due to the formation of crystals, their weight increases significantly, which leads to their falling to the ground. During flight, the frozen crystals are exposed to warm air currents, which contribute to their transition from solid to liquid. This is how drops of water reach the surface of the earth. This precipitation is called rain.
When exposed to air currents, clouds are transported over considerable distances, sometimes covering thousands of kilometers. In the process of colliding with each other, they unite. And when their mass becomes higher, the drops fall to the ground.
The interesting thing is that they have an identical shape. Only the size varies; it can reach 6 mm in diameter. Such drops are called drizzle. When they collide with the earth's surface, large drops break up, forming many small ones. Intense rainfall can be observed in the corners of the planet where evaporation occurs most. In hot climates, evaporation occurs faster, the surface heats up, which contributes to the transformation of steam into rain.
