Hey guys! Today we want to talk about “Layers of the Aatmosphere in Order” in solsarin. So, stay with us until the end of the text. Here we go!
The atmosphere of Earth is composed of layers with different properties, such as specific gaseous composition, temperature, and pressure. The lowest layer of the atmosphere is the troposphere, which extends from the planetary surface to the bottom of the stratosphere. The troposphere contains 75-80 per cent of the mass of the atmosphere, and is the atmospheric layer wherein the weather occurs; the height of the troposphere varies between 17km at the equator and 7.0km at the poles.
The stratosphere extends from the top of the troposphere to the bottom of the mesosphere, and contains the ozone layer, at an altitude between 15km and 35km. It is the atmospheric layer that absorbs most of the ultraviolet radiation that Earth receives from the Sun. The mesosphere ranges from 50km to 85km, and is the layer where in most meteors are incinerated before reaching the surface.
The thermosphere extends from an altitude of 85km to the base of the exosphere at 690km and contains the ionosphere, where solar radiation ionizes the atmosphere. The density of the ionosphere is greater at short distances from the planetary surface in the daytime and decreases as the ionosphere rises at night-time, thereby allowing a greater range of radio frequencies to travel greater distances.
Moreover, located in the thermosphere is the Kármán line at 100km, which is the boundary between outer space and Earth’s atmosphere. The exosphere begins at 690 to 1,000km from the surface, and extends to roughly 10,000km, where it interacts with the magnetosphere of Earth.
Atmospheric pressure is the force (per unit-area) perpendicular to a unit-area of planetary surface, as determined by the weight of the vertical column of atmospheric gases. In said atmospheric model, the atmospheric pressure, the weight of the mass of the gas, decreases at high altitude because of the diminishing mass of the gas above the point of barometric measurement. The units of air pressure are based upon the standard atmosphere (atm), which is 101.325kPa (760Torr, or 14.696pounds per square inch (psi).
The height at which the atmospheric pressure declines by a factor of e (an irrational number equal to 2.71828) is called the scale height (H). For an atmosphere of uniform temperature, the scale height is proportional to the atmospheric temperature, and is inversely proportional to the product of the mean molecular mass of dry air, and the local acceleration of gravity at the point of barometric measurement.
Layers of the atmosphere
The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500 km above the Earth’s surface is called the exosphere.
The different layers of the atmosphere
The atmosphere can be divided into layers based on its temperature, as shown in the figure below. These layers are the troposphere, the stratosphere, the mesosphere and the thermosphere. A further region, beginning about 500 km above the Earth‘s surface, is calling the exosphere.
Earth’s troposphere extends from Earth’s surface to, on average, about 12 kilometers (7.5 miles) in height, with its height lower at Earth’s poles and higher at the equator. Yet this very shallow layer is tasking with holding all the air plants need for photosynthesis and animals need to breathe, and also contains about 99 percent of all water vapor and aerosols (minute solid or liquid particles suspended in the atmosphere).
In the troposphere, temperatures typically go down the higher you go, since most of the heat found in the troposphere is generating by the transfer of energy from Earth’s surface. The troposphere is the densest atmospheric layer, compressed by the weight of the rest of the atmosphere above it.
Most of Earth’s weather happens here, and almost all clouds that are generating by weather are finding here, with the exception of cumulonimbus thunder clouds, whose tops can rise into the lowest parts of the neighboring stratosphere. Most aviation takes place here, including in the transition region between the troposphere and the stratosphere.
Located between approximately 12 and 50 kilometers (7.5 and 31 miles) above Earth’s surface, the stratosphere is perhaps best knowing as home to Earth’s ozone layer, which protects us from the Sun’s harmful ultraviolet radiation. Because of that UV radiation, the higher up you go into the stratosphere, the warmer temperatures become.
The stratosphere is nearly cloud- and weather-free, but polar stratospheric clouds are sometimes present in its lowest, coldest altitudes. It’s also the highest part of the atmosphere that jet planes can reach.
Above the stratosphere is the mesosphere. It extends upward to a height of about 85 km (53 miles) above our planet. Most meteors burn up in the mesosphere. Unlike the stratosphere, temperatures once again grow colder as you rise up through the mesosphere. The coldest temperatures in Earth’s atmosphere, about -90° C (-130° F), are finding near the top of this layer. The air in the mesosphere is far too thin to breathe (the air pressure at the bottom of the layer is well below 1% of the pressure at sea level and continues dropping as you go higher).
The layer of very rare air above the mesosphere is called the thermosphere. High-energy X-rays and UV radiation from the Sun are absorbing in the thermosphere, raising its temperature to hundreds or at times thousands of degrees. However, the air in this layer is so thin that it would feel freezing cold to us!
In many ways, the thermosphere is more like outer space than a part of the atmosphere. Many satellites actually orbit Earth within the thermosphere! Variations in the amount of energy coming from the Sun exert a powerful influence on both the height of the top of this layer and the temperature within it.
Because of this, the top of the thermosphere can find anywhere between 500 and 1,000 km (311 to 621 miles) above the ground. Temperatures in the upper thermosphere can range from about 500° C (932° F) to 2,000° C (3,632° F) or higher. The aurora, the Northern Lights and Southern Lights, occur in the thermosphere.
Although some experts consider the thermosphere to be the uppermost layer of our atmosphere, others consider the exosphere to be the actual “final frontier” of Earth’s gaseous envelope. As you might imagine, the “air” in the exosphere is very, very, very thin, making this layer even more space-like than the thermosphere.
In fact, the air in the exosphere is constantly – though very gradually – “leaking” out of Earth’s atmosphere into outer space. There is no clear-cut upper boundary where the exosphere finally fades away into space. Different definitions place the top of the exosphere somewhere between 100,000 km (62,000 miles) and 190,000 km (120,000 miles) above the surface of Earth. The latter value is about halfway to the Moon!
The ionosphere is not a distinct layer like the others mentioned above. Instead, the ionosphere is a series of regions in parts of the mesosphere and thermosphere where high-energy radiation from the Sun has knocked electrons loose from their parent atoms and molecules. The electrically charged atoms and molecules that are forming in this way are calling ions, giving the ionosphere its name and endowing this region with some special properties.
Earth’s atmosphere composition
The atmosphere of the earth has been making of many gases and these gases are usually calling ‘air’. How much amount of these gases are available in the earth’s atmosphere, is calling the composition of the earth’s atmosphere.
Earth’s atmosphere composition or percentage of gases in the atmosphere by volume are giving below:
- Nitrogen- 78.08%
- Oxygen- 20.95%
- Argon- 0.93%
- Carbon dioxide- 0.041%
- Water vapor- 0.0028%
- Neon- 0.0018%
- Other trace amounts of gases- such as Helium (He), Hydrogen (H2), Methane (CH4), Krypton (Kr), Ozone (O3), Xenon (Xe), and greenhouse gases.
These gases have some specific regions in the whole atmosphere. Ozone gas (O3) is found at a height of around 15 to 35 km in the stratosphere layer. Whereas Earth’s oxygen level or oxygen percentage in the atmosphere is around 20.95% by volume and is mostly found in the troposphere layer.
How Atmospheric Layers are Helpful for Life on Earth?
Each and every 5 layers of the atmosphere has its own benefits. The atmospheric layers help to sustain life on earth, from a life of a little insect to big living creatures including humans.
Here below you can find how these layers in order are helpful:-
- Troposphere – Within this layer humans and other lives live on the surface of the earth. Here we can see the weather and seasons.
- Stratosphere – This layer provides the best condition for the flying of jets and large airplanes.
- Mesosphere – This layer helps us by burning up most of the meteors in the sky. Here a rocket-powered aircraft can fly easily.
- Thermosphere – This layer helps us by burning space debris coming towards earth including obsolete satellites, meteors, and small-size asteroids.
- Exosphere – It helps us by providing the best condition to held satellites where it orbits around the earth.
So these were the 5 layers of the atmosphere and how these layers are different from each other. All these five layers of the atmosphere help to sustain life on the earth including with magnetosphere.