Which of the following is correct regarding mesosphere? I. This is the third layer of the atmosphere. II. Meteorites burn up in this layer on entering from the space.
Understanding the Mesosphere: Earth's Atmospheric Layers
The Earth's atmosphere is divided into several layers based on temperature variations. Understanding these layers helps us comprehend different atmospheric phenomena.
Analyzing Statement I: Position of the Mesosphere
Statement I says, "This is the third layer of the atmosphere." Let's list the main layers of the Earth's atmosphere starting from the surface:
- Troposphere (closest to Earth's surface, where weather occurs)
- Stratosphere (contains the ozone layer)
- Mesosphere
- Thermosphere
- Exosphere (outermost layer, merges into space)
Based on this order, the mesosphere is indeed the third major layer of the atmosphere, located above the stratosphere and below the thermosphere. Therefore, Statement I is correct.
Analyzing Statement II: Meteorite Burning in the Mesosphere
Statement II says, "Meteorites burn up in this layer on entering from the space." The mesosphere is characterized by decreasing temperature with altitude, making it the coldest layer of the atmosphere. When meteoroids from space enter the Earth's atmosphere, they encounter increasing air density as they descend. This friction with the air causes them to heat up rapidly and burn, creating what we see as meteors or "shooting stars." The majority of this burning process occurs within the mesosphere, between altitudes of about 50 km and 85 km. Therefore, Statement II is also correct.
Conclusion on Mesosphere Characteristics
Both statements accurately describe characteristics of the mesosphere:
- It is the third layer of the Earth's atmosphere.
- It is the region where most meteoroids burn up upon entering the atmosphere.
Since both statements I and II are correct regarding the mesosphere, the correct option is the one that affirms both.
| Layer | Approximate Altitude Range | Key Characteristics |
|---|---|---|
| Troposphere | 0 - 15 km | Weather occurs here, temperature decreases with height. |
| Stratosphere | 15 - 50 km | Contains ozone layer, temperature increases with height. |
| Mesosphere | 50 - 85 km | Third layer, meteorites burn up, coldest layer. |
| Thermosphere | 85 - 600 km | Temperature increases with height, contains ionosphere, aurora occurs here. |
| Exosphere | > 600 km | Outermost layer, transitions to space, very thin air. |
Revision Table: Mesosphere Facts
| Aspect | Detail about Mesosphere |
|---|---|
| Layer Order | Third layer (above Stratosphere, below Thermosphere) |
| Altitude | Approx. 50 km to 85 km |
| Temperature Trend | Decreases with increasing altitude (coldest layer) |
| Key Phenomenon | Burning up of meteoroids/meteorites |
Additional Information: Atmospheric Phenomena
Beyond the mesosphere, other atmospheric layers host unique phenomena:
- Stratosphere: Contains the ozone layer, which absorbs harmful UV radiation from the sun. Commercial airplanes often fly in the lower stratosphere to avoid turbulence in the troposphere.
- Thermosphere: Home to the International Space Station (ISS) and satellites. It also contains the ionosphere, a region of charged particles important for radio wave propagation. The aurora borealis and aurora australis (Northern and Southern Lights) occur in the thermosphere.
- Exosphere: The very thin upper limit of the atmosphere, where atmospheric gases gradually merge into the vacuum of space.
Each layer plays a vital role in protecting life on Earth and influencing atmospheric processes.
Important Questions from Environment
How many Ramsar conservation have been enlisted from India so far? (as of 2019)
Which of the following statement is correct?
I. Converting kitchen waste into compost through worms or red earthworms is called vermicomposting.
II. It is not possible to convert plastics into less harmful substances by composting.
Where have a team of scientists from Delhi University and the Wildlife Institute of India discovered a new species of ‘paddy frog’ in June 2019?
Which of the following statement is correct?
I. CO 2is not a greenhouse gas.
II. Clean and drinkable water is called drinking water.
Which of the following conferences works for the prevention of desertification?
