Earth is surrounded by the atmosphere, a gaseous layer divided into numerous layers or strata. The subject of the atmosphere is essential for preparing for competitive exams like the SAT, SSC CGL, RRB, or other academic exams. Therefore, each applicant must thoroughly prepare for this subject. This article will finish your search if you want a quick review or want to learn more about this topic.
The atmosphere of Earth is stratified, and each layer has unique characteristics. The troposphere, stratosphere, mesosphere, and thermosphere are the four layers of the Earth's atmosphere and are differentiated by temperature.
While fascinating occurrences like the stunning aurora occur higher in the atmosphere, weather processes happen in the lower layers. We may learn about the functioning of the atmosphere by comprehending how the atmosphere's temperature varies with height.
Let's get familiarized with the layers of the atmosphere in this article.
Structure of the Atmosphere
The temperature variations are erratic, in contrast to the pressure and density changes, which decrease with altitude. Temperature gradients are used to describe temperature changes over a distance. The temperature differential within each layer separates the Earth's atmosphere into layers, and each layer's heat source controls its temperature gradient.
From the bottom up, the gaseous shell encircling the Earth changes. Using this, it was possible to identify five different levels.
They are thermal properties (temperature variations), chemical composition, motion, and density.
The most significant changes in thermal properties, chemical composition, mobility, and density occur at the "pauses" that separate each layer.
Based on temperature, the atmosphere is divided into strata. The troposphere, stratosphere, mesosphere, and thermosphere are these layers. The exosphere is another zone located 500 kilometres above the Earth's surface.
Now, Let us move toward the different layers of the Atmosphere along with the detailed information about their features and properties.
Even though sunlight touches the Earth's surface from top to bottom, the troposphere is primarily heated at the bottom. The Earth's surface is far better at absorbing different types of solar energy than the air.
As the hot air parcel ascends, it expands and cools the surrounding air. The base of the troposphere is warmer than its base because the atmosphere on Earth's surface absorbs the sun's energy, heats up, and then climbs upward, where it cools off.
The boundary layer is the lowest layer of the troposphere. Here, the Earth's surface characteristics control how the air moves.
The wind's movement across the Earth's surface and the thermals that rise from the ground when warmed by the sun cause turbulence. This turbulence redistributes heat and moisture, pollution, and other atmospheric elements within the boundary layer.
The tropopause is the term for the top of the troposphere. It is 7 to 10 kilometres above the surface of the Earth in the poles, where it is at its lowest. Near the equator, it is tallest (at 17 to 18 km).
The stratosphere rises to 50 km and is located above the troposphere. There are no clouds or other weather-related phenomena in this stratum. Aircraft fly in the Stratosphere for a comfortable journey as a result. The ozone layer, which shields us from the sun's harmful radiation, is also in the stratosphere.
High-energy UV radiation from the sun is absorbed by ozone molecules in the stratosphere and converted to heat. Because of this, the stratosphere warms up as you ascend, unlike the troposphere.
The ozone in the stratosphere shields humans from skin cancer and other health problems by absorbing harmful UV rays. The amount of ozone in the stratosphere, particularly at polar latitudes, has decreased due to chemicals (called CFCs or freons and halons) that were once used in refrigerators, spray cans, and fire extinguishers, creating the so-called "Antarctic ozone hole."
Since humans no longer produce the most dangerous CFCs, we anticipate the ozone hole will slowly close over the twenty-first century.
With increasing altitude, the mesosphere's temperature drops. This is due to the mesosphere's shortage of gas molecules that may absorb solar light. The stratosphere below is the only source of heat. The mesosphere is quite cold, particularly at the top, where it can go as hard as -90°C.
The ozone layer that gives UV protection is in the stratosphere below. Therefore, an astronaut travelling through the mesosphere would suffer from severe sunburns. When meteorites enter the atmosphere from space, they ignite in this layer.
The thermosphere has a relatively low molecular density. One gas molecule can travel roughly one kilometre without running into another one. The air seems cold because there is so little energy being exchanged. In the upper thermosphere, satellites can be seen orbiting.
The ionosphere is located within the thermosphere. The ionosphere comes from the solar energy that ionizes gas molecules to create a positively charged ion and one or more negatively charged electrons. The ionosphere is traversed by electric currents produced by these freed electrons.
These free ions provide the ionosphere with some intriguing characteristics. The aurora, sometimes called the Northern and Southern Lights, occurs in the Earth's ionosphere.
The outermost limit of the Earth's gaseous envelope is the exosphere. The layers of the Earth's atmosphere are not clearly distinguished from space. Exosphere air continuously but gradually escapes from Earth's atmosphere and enters space.
We Hope you now have a solid understanding of the layers of the Atmosphere after reading this blog.