- What is rain?
- How is rain formed?
- What is the rain for?
- types of rain
- What consequences does the rain have?
- Acid rain
We explain what rain is, how it forms and its positive and negative consequences. Also, what is acid rain.
What is rain?
the rain or precipitation It is one of the most usual, recurrent and necessary atmospheric phenomena that take place on our planet. But we must think of it as the most visible part of a much larger circuit: the hydrological cycle, in which the Water of our planet changes fitness and circulates through various environments.
Rainwater falls in the form of small round drops, about 0.5 to 6.3 mm in diameter (or even smaller, depending on the type of precipitation), formed in the clouds that are in the lowest portion of the atmosphere.
When its size is right, the gravity It acts on them by making them fall towards the earth's surface at a speed of between 8 and 32 km/h, to later be absorbed by the earth or remain on other surfaces until they evaporate.
Human beings have observed rain since time immemorial and for centuries gave it very different meanings and mythological or religious explanations. However, it was thanks to modern science that we have proof of the enormous importance of rain for the stability of the planet.
The study of rain is known as pluviometry and uses devices such as pluviometers, with which the amount of falling water is measured. Information on precipitation is also key to the study of atmospheric conditions and for the formation of climate models.
How is rain formed?
Rain is the product of condensation of water steam on the atmosphere. That is, the vapor accumulates in different types of clouds (generally nimbostratus and cumulonimbus), since the vapor tends to rise and cool in the atmosphere.
Once there, the clouds gain higher and higher density until the water reaches the critical mass necessary to be attracted by the gravity and rush down from above, distributing themselves irregularly.
For this, however, the atmospheric conditions of Pressure Y temperature they must be correct, since a sudden drop in temperature could totally or partially freeze the water suspended in the clouds, and instead of rain, frost, snow or hail would fall.
What is the rain for?
Rain is essential for the stability of the life as we know it. In the first place, because when the water circulates (heating and evaporating, then cooling and falling again) not only cools the atmospheric temperature and allows a climate more uniform and even.
In addition, it cleans air suspended particles, for example, in the pollution. However, this can lead to secondary problems, as most pollutants they are then transferred by rain to the ground or to rivers and seas.
On the other hand, rain is indispensable for plant life. Only regular rain allows forests Y jungles continue your pace of life. That is why, in places where it rarely rains, there are deserts and life is scarce in comparison.
Also, the rain erodes rocks and minerals, and thus drags inorganic nutrients in its path that serve as food for plant and even animal species. In fact, she is involved in the biogeochemical cycles of carbon, the match and other organic elements.
types of rain
There are two main criteria by which to classify rain. First of all, there is the way they are formed, from the rise of atmospheric air masses. Second, there is the factor of the intensity with which they occur. Let's look at each one separately:
Types of rain according to its formation. There are three types of rain, which are:
- Convection rains, produced when the air near the earth's surface heats up and expands, rising in the atmosphere to regions where it cools, condenses and gives way to precipitation. This type of rain is typical of the warmest regions of the planet and the summer of the temperate zone.
- Orographic rains, produced when a mass of moist air meets a relief mountainous and, on its way up the slope, it cools down and rains. from the other side of the mountainInstead, the air descends warmer and drier, so there is no rain.
- Cyclonic or frontal rains, produced when two air masses of different temperatures meet face to face and a cyclonic dynamic occurs between them, that is, rotating, which brings with it bad weather and torrential precipitation. This rain is typical of hurricanes and other atmospheric phenomena of intensity.
Types of rain according to its intensity. The following types of rain are distinguished:
- Rain or ordinary rain, generally weak to moderate, would be the "standard" rain.
- Drizzle or garúa, very weak rain with very fine drops, which spray into the air and often do not touch the ground.
- Shower or downpour, moderate or intense rain but of very short duration, occasionally accompanied by wind.
- Downpour or torrential rain, rain of great intensity, although for a short time, like a very intense downpour.
- Storm rain, rain of variable intensity (ranging from moderate to heavy) but long duration, generally accompanied by other atmospheric phenomena, such as intense winds or electrical discharges.
What consequences does the rain have?
The rain, like all natural phenomena, can have very positive or very negative consequences, depending on the type of rain and the frequency and intensity with which it occurs. Some of these consequences are as follows:
positive consequences
- It cools and humidifies the air in the atmosphere, allowing a stable and less extreme climate cycle. It is for this reason that life in the vicinity of the coasts tends to be more friendly, since the humidity allows more uniform climates.
- It redistributes the water on the planet, taking it from its gaseous state to the liquid and sometimes to solid, which contributes to a more homogeneous distribution of humidity on the planet.
- It drags in its path organic and inorganic nutrients necessary for life and for other biogeochemical cycles.
- Allows the spontaneous growth of vegetation and contributes to the support of the biosphere.
Negative consequences
- Heavy rains and for a very long time (as in the case of storms or hurricanes) can bring with it floods and overflowing of rivers, lagoons and lakes. This can also occur in soils with low absorptive capacity, despite not having large bodies of water nearby.
- Rain erosion can contribute to the production of landslides, landslides and other natural disasters in complicated geographies. It can also, given enough time, destroy human buildings.
- In the case of highly polluted atmospheres, rain can cause chemical reactions dangerous and drag along toxic substances, as in the case of the acid rain.
Acid rain
Acid rain is a phenomenon caused by air pollution with gases or solid materials in suspension. This contamination is typical of human industrial activity or rash of some volcanoes.
Suspended toxic materials are picked up by water droplets and react with moisture. This gives rise to different forms of acid (such as sulfuric acid or hydrochloric acid) which then fall together with the water droplets.
This type of toxic rain intensely degrades plant life, since the diluted acid in the water corrodes leaves and bark, as well as poisoning the water and acidifying the soil, turning the ecosystems more arid and less habitable.