Correct Option
The correct sequence of atmospheric layers from the Earth's surface upwards is Troposphere, Stratosphere, Mesosphere, and Ionosphere.
- Troposphere: This is the lowest layer, extending up to approximately 8 km at the poles and 18 km at the equator. Almost all weather phenomena occur within this layer. Temperature generally decreases with increasing altitude.
- Stratosphere: Located above the troposphere, it extends up to about 50 km. This layer contains the ozone layer, which absorbs harmful ultraviolet radiation from the Sun. Temperature increases with altitude in the stratosphere due to ozone absorption.
- Mesosphere: Above the stratosphere, it extends up to approximately 80 km. Temperatures decrease with altitude, making it the coldest layer of the atmosphere. Meteors typically burn up in this layer.
- Ionosphere: This is an electrically charged region that overlaps parts of the mesosphere and thermosphere, extending from about 80 km to 400 km. It is characterized by the presence of ions and free electrons, which enable the reflection of radio waves back to Earth, crucial for long-distance radio communication.
Incorrect Options
Options (A), (B), and (D) present incorrect sequences of atmospheric layers.
- Option (A) Troposphere, Stratosphere, Ionosphere, Mesosphere: This sequence incorrectly places the Ionosphere before the Mesosphere. The Mesosphere is situated below the Ionosphere in the correct order.
- Options (B) Stratosphere, Troposphere, Ionosphere, Mesosphere and (D) Stratosphere, Troposphere, Mesosphere, Ionosphere: Both these options are incorrect as they begin with the Stratosphere. The Troposphere is the lowest layer of the atmosphere, directly above the Earth's surface, and must be the first layer in the sequence from the surface upwards.