Which of the following is the closest layer to the Earth's surface in which all weather occurs?

The correct answer is Troposphere.

Key Points

• The troposphere is the lowest part of the Earth's atmosphere in which all tropical changes take place. 
• It contains about 75% of the total air in the atmosphere.
• Based on temperature variation, our atmosphere can be classified into the following layers mainly.
• Troposphere: From Earth's surface up to 10km. Here, temperature decreases with increasing height. We, humans, live in the troposphere, and nearly all weather occurs in this lowest layer. Most clouds appear here.
• Stratosphere: From 10km above the surface to 50km above the surface, Here, temperature increases with increasing height due to the presence of the ozone layer.
• Ozone gas is capable of absorbing harmful UV rays and due to the absorption, the temperature increases.
• All the airplanes fly in this zone as due to high temperature there is less turbulence and hence smoother flights are possible. 
• Mesosphere: From 50km above the surface to 85 km above the surface. Here, the temperature again decreases with increasing height. Most meteors burn up in the mesosphere.
• Ionosphere: Beyond 85km there is a thermosphere layer and Ionosphere is a series of regions in parts of the mesosphere and thermosphere.