Earth Atmosphere

The Atmosphere

The Earth’s atmosphere comprises different gases that cover the planet like a blanket. It’s in many layers. The part of the atmosphere that we are able to see from the land which has the clouds, the rainbow, birds and airplanes, kites is actually only a thin layer when compared to the full size of the Earth. The Earth is huge spherical ball slightly tilted on its axis, third in position in the Solar System.  The radius of the Earth is roughly about 6400 kms, but all our airplanes can go as high as 16 kms only which is hardly anything when compared to the whole of the Earth.

Credit: https://www.thinglink.com/scene/659758625421524992

The mesosphere is above the stratosphere and reaches from around 48-55 kms above the ground up to 80-85 kms. It becomes quite cold here and that the little drops of water vapor found here sublimates directly into clouds.  Cloud formation does not happen anywhere after this layer.

The thermosphere is the next layer also called the ionosphere because of the presence of ions in this layer. It starts from 80-85 kms up until 490kms to 900kms. The International Space Station orbits in this layer. This is where we find the auroras that people see from Earth near the North and South poles.  The size of the thermosphere depends on how hot the Sun is at a time. Temperature here increases drastically, but there is no proper way to calculate this; because of the presence of very few molecules in this layer and also that they’re moving rapidly.  There are no clouds in this layer.

Finally, the exosphere is the uppermost and the last layer of the atmosphere. This is where atoms and molecules escape Earth’s gravity into space.

Credit: https://www.thinglink.com/scene/573149755392131074

Greenhouse Gases and Ozone

Gases like water vapor, carbon dioxide and methane are green house gases which are present in the small amounts. Like a thick blanket that covers Earth, they are especially good at trapping heat. And because their concentrations are increasing due to human activity, more heat than ever is being trapped underneath these gases and  the Earth overall is warming. This is termed as the Greenhouse Effect.

Check Point

Fill in the blanks:

1. As we go up from the surface of the Earth, the air pressure gradually …………………
2. ………… contains most of the clouds, weather, air planes, and air currents in the Earth’s atmosphere.
3. …………….has the ozone layer.
4. The is the coldest layer in the atmosphere is……………..
5. The …………… is the uppermost layer of the atmosphere. This is where atoms and molecules escape Earth’s gravity into space.

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