Introduction to Atmosphere

An atmosphere is the surrounding of any planet usually consists of gases which is there due to the gravity of that planet. Here in this article we are more interested in the atmosphere of Earth , so we will talk only about it. But we will definitely look into other planets as well.

Mass of Earth’s atmosphere is about 5.5x10¹⁸ Kgs. However you will be surprised to know that 99% of it is within 32 Km from the surface. Atmosphere is comprised of layers based on temperature.

Let’s deep dive into all of these layers and discuss about each separately :

1. TROPOSPHERE : It is closest to Earth, where we live. 75% mass of atmosphere lies in this region. Troposphere is the wettest layer of the atmosphere while above layers contains very less moisture. The bottom of the Troposphere is earth’s surface and the upper boundary is called Tropopause. Temperature decreases as we go higher in altitude , and the temperature drop is about 6.5 Degrees for 1 Km. Pressure and Density also decreases with increase in altitude.
2. STRATOSPHERE : It is the second layer of atmosphere as we go upwards. The lower boundary of Stratosphere is Tropopause and the upper boundary is stratopause. Ozone layer is located in this region. Ozone absorbs energy from incoming UV radiation from the Sun which cause in heating the layer. Air is roughly 1000 times thinner at the top of the stratosphere than air at sea level. Because of this, jet aircraft and weather balloons reach their maximum operational altitudes within the stratosphere.
3. MESOSPHERE : Mesosphere is above the Stratosphere. Temperature decreases with higher altitude in Mesosphere. The bottom of the Mesosphere is Stratopause and the top most part is called Mesopause. Aircrafts and balloons can’t fly high enough to reach this layer and Satellites orbit above this layer , so it is little bit difficult to study. This layer protects Earth from meteoroids.
4. THERMOSPHERE : Thermosphere is above Mesosphere. Solar activity strongly influences temperature in the thermosphere. Temperature is very high in this region which lies between 500–2000° C. Air density is so low in this region, So we consider it outer space. The space shuttle and the ISS (International Space Station) both orbit Earth within the thermosphere. The aurora (the Southern and Northern Lights) primarily occur in the thermosphere.
5. MAGNETOSPHERE : A magnetosphere is the region around a planet dominated by the planet’s magnetic field. Other planets in our solar system have magnetospheres, but Earth has the strongest one of all the rocky planets: Earth’s magnetosphere is a vast, comet-shaped bubble, which has played a crucial role in our planet’s habitability. Life on Earth initially developed and continues to be sustained under the protection of this magnetic environment. The magnetosphere shields our home planet from solar and cosmic particle radiation, as well as erosion of the atmosphere by the solar wind (the constant flow of charged particles streaming off the sun).

Variation of Temperature with Altitude : (We should keep it in mind that Pressure and Density decreases with increase in altitude.)

I hope you must have learnt something from this article. Hope to see you in next article where we will explore new things .

Thank You !!