21 natural phenomena explained and their classification

Natural phenomena are those events that occur spontaneously in nature without human intervention. They are governed by the laws of physics and, although they seem extraordinary at times, they are quite common on our planet. Therefore, we put together a list with the most interesting examples of natural phenomena and their explanation.

1. Auroras

Polar auroras are luminous phenomena that appear in the highest part of the atmosphere in the form of arches, bands, curtains and folds. Most auroras appear white with shades of green or yellowish-green.

Auroras occur in the vicinity of the Earth's magnetic poles, where atmospheric gases react with electrically charged particles from solar flares.

The auroras were named after the famous Galileo Galilei, in honor of the Roman goddess of dawn, Aurora. In the northern hemisphere they are known as aurora borealis (boreal), while in the southern hemisphere they are known as aurora australis (austral).

2. Rainbow

Rainbows are optical phenomena that form concentric arcs of colors on a "screen" of water droplets in the atmosphere. They are due to the reflection and refraction of sunlight within the drop of water.

The size of the drops determines which colors are present in the rainbow and the bandwidth occupied by each one. In all cases, the violet is always on the inner arc and the red is outward. The colors of the rainbow are: red, orange, yellow, green, blue, indigo, and purple.

The primary rainbow is produced opposite to the source of light that produces it and its center is in the prolongation of the line connecting the observer and the light source, Also, the sky is darker outside the Rainbow.

Sometimes a second rainbow is less bright than the primary rainbow, where red is on the inside and purple is on the outside.

3. Eclipses

Eclipses are astronomical phenomena that occur when a celestial body is partially or completely obscured by another star. This occurs when three heavenly bodies align. From Earth we can see two types of eclipses:

• solar eclipse: Occurs when the Sun is darkened because the Moon stands between the Earth and the Sun.
• lunar eclipse: Occurs when the Moon gets dark because the Earth stands between the Sun and the Moon.

4. Shooting Stars

A shooting star is the popular name for meteors, astronomical phenomena consisting of particles or rocks that enter the upper layer of the Earth's atmosphere. Upon entering, the meteors are heated by friction, leaving a luminous trail that is seen as a streak of light in the sky that quickly disappears.

The fastest meteor shower is that of the Leonids, which occurs between November 15 and 20 of each year. They are the product of Comet 55P / Tempel-Tuttle whose orbit passes opposite the movement of the Earth's orbit around the Sun.

5. Hail

Hail is a hydrological phenomenon. It consists of a precipitation of ice particles, usually with spherical, conical or irregular shapes and diameters between 5 mm and 5 cm.

Hail rain always occurs as a shower or shower during heavy storms. Hailstones form around a small core of snow that collects raindrops.

6. Mirage

Mirages are optical phenomena that give the illusion of water mirrors on flat surfaces. These are produced when light rays pass through layers of air with differences in density. This difference in density in air is due to differences in temperature, and as a consequence, the refractive index changes, which is why light produces a curvature.

Mirages are generally observed when the temperature of the Earth's surface differs markedly from the temperature of the air above it. They can occur on intensely hot water surfaces, soil, beaches, roads, and other flat surfaces.

7. Halo

Halo phenomena are a group of optical phenomena in the form of rings, arcs, or bright spots around the Sun. They are produced by the reflection and refraction of light through ice crystals suspended in the atmosphere.

8. Twilight rays

Twilight rays are a luminous phenomenon They appear as dark bluish streaks that radiate from the Sun when it sets. They are the result of the shadows of the clouds found, on the horizon or below it.

9. Tides

The tides are a hydrological natural phenomenon, the result of the up and down movement of the surface of the oceans by the force of attraction of the Moon on the Earth. The water of the oceans when it faces the Moon is attracted towards it, increasing the level of the ocean surface.

As the Earth rotates on its axis it exposes other ocean surfaces. The Moon is also rotating around the Earth, so it takes 24 hours and 52 minutes for all points on the planet to face the Moon. When this happens, we are at high tide.

You may also be interested in seeing Moon phases.

10. Waves

The waves are a hydrological natural phenomenon created by the wind. Wind friction on calm water transfers some of the wind's energy to the water, forming waves. The size of the waves is determined by the force of the wind, in such a way that the stronger the wind, the larger the wave.

The waves can reach heights as impressive as 34 meters, the equivalent of a 12-story building. The wave surfing record is held by Brazilian Rodrigo Koxa, who on November 8, 2017 rode a 24.38 m wave off the Atlantic coast of Portugal.

11. tsunami

A tsunami is a single high-energy wave that travels at high speed through the ocean, caused by earthquakes, volcanoes, or other disturbances on the ocean floor. The most devastating tsunami was recorded on December 26, 2004 off the coast of Indonesia, in the Indian Ocean.

12. Cyclones

Cyclones are storms with strong winds that rotate counterclockwise. They are atmospheric phenomena which are classified into:

• Hurricanes: cyclonic storms with winds of more than 120 kilometers per hour that occur in the Atlantic Ocean.
• Typhoons: they are cyclones that occur in the Pacific Ocean.

Cyclones are the result of:

• Rotation of the Earth: the movement of the Earth on its axis causes the atmosphere to swirl and flow.
• Solar warming of the oceans: solar heating impacts with greater intensity in tropical regions, causing the oceans to act as heat engines.
• Air heating: As the ocean warms, the air over the ocean surface heats up.
• Air movement: the hot air rises while the cold air falls, causing spirals of masses of hot and humid air upwards, condensing the water into clouds.

As the storm grows, it spreads around a central eye that looks like a galaxy from above.

13. Monsoon

Monsoons are weather phenomena consisting of seasonal winds driven by warming of the Earth's surface. There are summer and winter monsoons, with opposite directions that occur in South Asia, Africa, Australia and the west coast of Central America. They blow from cold regions to relatively warm regions.

Summer monsoons in South Asia blow from the cold Indian Ocean towards the hot land in a northeast direction. This happens between May and September. The humid wind that comes from the sea is associated with an increase in the frequency and intensity of the rains.

The winter monsoons in South Asia blow in a southwesterly direction, from the cooling land to the now warm ocean. During this time, the weather is sunny and dry.

14. Twister

Tornadoes are atmospheric phenomena that occur on earth. They are violent winds that spiral in a funnel from the clouds to the ground.

The widest tornado on record measured 4.18 km and occurred in Oklahoma (USA). USA) on May 31, 2013.

15. The boy and the girl

The Boy and the Girl are weather phenomena produced by changes in the surface temperature of the tropical Pacific Ocean, known as ENSO (for its acronym in English El Niño-Southern Oscillations). El Niño is associated with the warm phase with prolonged droughts, while La Niña appears as the coldest phase of the cycle, with more frequent rains than normal in some regions.

16. Electric storms

Thunderstorms are atmospheric phenomena that can occur in any region of the planet. They are associated with convective clouds with one or more electrical discharges, which manifest as a flash of light (lightning) and a roar (thunder).

17. Flash of lightning

Lightning is a luminous manifestation accompanied by a sudden electrical discharge that occurs on or within a cloud.

During a storm, in the clouds a separation of charges takes place, accumulating positive charges in the upper part and negative charges in the lower part. This separation of charges produces a strong electric field within the cloud as well as between the cloud and the Earth.

The difference in charge between the clouds and the Earth creates an initial charge flow, which heats the air and ionizes some of the atoms in the air. The heating and ionization of the air by the electrical discharge produces the lightning that we can see. Soil and moist air are good electrical conductors.

There are three types of lightning:

1. Discharges to the ground: occur between the clouds and the ground.
2. Discharges to clouds: occur within storm clouds.
3. Discharges to the air: occurs between the clouds and the air, not touching the ground, almost horizontally.

18. Thunder

Thunder is a acoustic phenomenon which is presented as a rumbling sound that accompanies the lightning. Due to the difference between the propagation speeds of light and sound, lightning is seen before the associated thunder is heard. The time interval increases with increasing distance between the site of discharge and the observer. When the distance is greater than 20 km the thunder is not heard.

19. Thermal waters

The hot springs are a hydrological and geological phenomenon where the water is warmer than the temperature of the human body. The water in these places can be heated in two ways:

1. Circulating near a magma chamber: In regions where there are volcanoes, hot springs can occur, such as the boiling lake in Dominica and the Yellowstone national park in the USA.
2. Circulating deep in the Earth: water 2 or 3 km deep is much warmer than water on the surface, as in the Ojocaliente hot springs in Aguascalientes (Mexico).

20. Earthquake

Earthquakes are geological phenomena result of deep disturbance in the earth, the consequence of which is the movement and shaking of the ground. Earthquakes are created by the friction or collision of the tectonic plates of the earth's crust.

Earthquakes occur in regions known as faults, areas on the Earth's surface where plates collide. The American continent is affected by the San Andreas fault (California, USA) and the Pacific ring of fire.

21. Migrations

Migration is a biological phenomenon characterized by the movement of animals over long distances with changes in the season. This is an innate behavior that evolved as an adaptation due to the availability of resources. Migration phenomena are seen in turtles, fish and birds, among others.

An emblematic case of migration is that of the Arctic swallow (Sterna paradisaea). This bird breeds in the summer from the Northern Arctic Circle and then migrates south to the Antarctic Circle, covering a distance of more than 80 thousand kilometers.

It may interest you to know what they are Solstice and equinox.

Classification of natural phenomena

We can observe these phenomena in the sky, on the ground, in the air, in the sea and in the biosphere. In this way we can classify natural phenomena as:

• Geological phenomena: are those events that we can observe in the earth's crust, such as earthquakes.
• Hydrological phenomena: are those phenomena where water intervenes, such as hot springs and hail.
• Atmospheric phenomena: events that are determined by atmospheric composition and condition, such as tornadoes.
• Biological phenomena: are those events that involve living beings, their behaviors and interactions, such as animal migrations.
• Astronomical phenomena: are those phenomena that occur in space and that we can observe on Earth, such as eclipses and shooting stars.
• Optical phenomena: are the phenomena that result from the distortion of light beams, as in mirages and halos around the Sun.
• Luminous phenomena: are those where there is light emission, as in the auroras.
• Acoustic phenomena: are those phenomena related to sounds, such as thunder.

It may interest you Physical and chemical phenomena.

References

Andrews, T. (2004) Wonders of the Air. London, UK. Libraries Unlimited.
Guinness World Records 2019 (2018). Guinness World Records Limited.
Haven, K. (2005). Wonders of the Sea. London, UK. Libraries Unlimited.
Haven, K. (2006). Wonders of the Land. London, UK. Libraries Unlimited.