The coldest layer of the atmosphere, known as the mesosphere, lies above the stratosphere and below the thermosphere, extending from approximately 50 to 85 kilometers above Earth’s surface. This region is characterized by extremely low temperatures, with the coldest point occurring at the mesopause, the boundary between the mesosphere and thermosphere, where temperatures can reach as low as -90 degrees Celsius.
The Frigid Middle: Earth’s Coldest Atmospheric Layer
The atmosphere, the gaseous blanket surrounding our planet, is not a uniform entity. It is divided into distinct layers based on temperature and composition. The coldest of these layers is the mesopause, located at the boundary between the mesosphere and the thermosphere.
Mesosphere
The mesosphere extends from about 50 to 85 kilometers above Earth’s surface. As you ascend through the mesosphere, the temperature drops dramatically. This decrease in temperature is caused by the absorption of solar radiation by ozone and carbon dioxide molecules in the atmosphere.
Mesopause
At the top of the mesosphere is the mesopause, the coldest part of Earth’s atmosphere. The temperature at the mesopause can drop to as low as -100 degrees Celsius (-148 degrees Fahrenheit). The extreme cold at the mesopause is caused by the lack of significant absorption of solar radiation and the efficient cooling of gases through radiative heat loss.
Thermosphere
Above the mesopause is the thermosphere, which extends from about 85 to 600 kilometers above Earth’s surface. Unlike the mesosphere, the thermosphere experiences a temperature increase with altitude. This increase in temperature is caused by the absorption of solar ultraviolet radiation.
Temperature Profile of the Atmosphere
The following table summarizes the temperature profile of Earth’s atmosphere:
| Layer | Altitude (km) | Temperature Range (Celsius) |
|---|---|---|
| Troposphere | 0-10 | -56 to 15 |
| Stratosphere | 10-50 | -56 to -2 |
| Mesosphere | 50-85 | -2 to -100 |
| Mesopause | 85 | -100 |
| Thermosphere | 85-600 | -100 to 1,500 |
Question 1:
What layer of the Earth’s atmosphere experiences the lowest temperatures?
Answer:
Subject: Coldest layer of the Earth’s atmosphere
Predicate: Experiences the lowest temperatures
Object: Mesosphere
Question 2:
At what approximate altitude can the coldest temperatures in the Earth’s atmosphere be found?
Answer:
Subject: Coldest temperatures in the Earth’s atmosphere
Predicate: Can be found
Object: Approximately 80 kilometers (50 miles) above sea level
Question 3:
Why is the mesosphere the coldest layer of the atmosphere?
Answer:
Subject: Mesosphere
Predicate: Is the coldest layer of the atmosphere
Object: Because it receives little heat from either the sun or the Earth’s surface
And there you have it, folks! The coldest layer of our atmosphere is the stratosphere, which sits about 10 to 30 miles above the surface. Thanks for hanging out with me today. If you’ve got more questions about this fascinating topic, feel free to drop me a line. And don’t forget to come back soon for more mind-boggling adventures in the world of science!