Mesosphere

Definition

The mesosphere is the third layer of Earth's atmosphere, located above the stratosphere and below the thermosphere, extending from about 50 to 85 kilometers above sea level. This layer is characterized by decreasing temperatures with altitude and is where most meteorites burn up upon entering Earth's atmosphere, creating bright streaks known as meteors.

5 Must Know Facts For Your Next Test

1. In the mesosphere, temperatures can drop to as low as -90 degrees Celsius (-130 degrees Fahrenheit), making it one of the coldest layers of the atmosphere.
2. This layer is where most meteoroids disintegrate before reaching the Earth's surface, preventing potential impacts.
3. The mesosphere is also home to noctilucent clouds, which are ice clouds that form at very high altitudes and are best seen during twilight.
4. Due to its altitude, weather balloons cannot reach the mesosphere, and it's difficult to study this layer directly from the ground.
5. The boundary between the mesosphere and the thermosphere is called the mesopause, which marks a transition to higher temperatures in the thermosphere.

Review Questions

• How does the temperature profile in the mesosphere compare to that of the stratosphere and thermosphere?
  • In the mesosphere, temperatures decrease with increasing altitude, reaching some of their lowest values near the mesopause. In contrast, temperatures in the stratosphere increase due to the presence of ozone that absorbs ultraviolet radiation. When moving up to the thermosphere, temperatures begin to rise again significantly due to intense solar radiation absorption. This distinct temperature gradient across these layers affects atmospheric processes and phenomena.
• What role does the mesosphere play in protecting Earth from meteoroids and how does this affect our understanding of atmospheric science?
  • The mesosphere acts as a protective barrier for Earth by being the region where most meteoroids burn up upon entering the atmosphere. This destruction of meteoroids before they reach the surface prevents potential impacts that could be damaging. Understanding this process highlights the importance of atmospheric layers in safeguarding life on Earth and informs scientists about atmospheric composition and dynamics.
• Evaluate how studying the mesosphere can contribute to advancements in atmospheric science and technology.
  • Researching the mesosphere can lead to significant advancements in atmospheric science by improving our understanding of atmospheric dynamics and chemical interactions at high altitudes. This knowledge is crucial for developing technologies such as satellite communication and navigation systems that rely on atmospheric conditions. Additionally, studying phenomena like noctilucent clouds provides insights into climate change effects at high altitudes, allowing for better predictive models regarding global climate patterns.

Related terms

Stratosphere: The layer of the atmosphere directly above the troposphere, extending from about 10 to 50 kilometers, where temperature increases with altitude due to the presence of ozone.

Thermosphere: The atmospheric layer above the mesosphere, extending from about 85 kilometers to 600 kilometers, known for its high temperatures and low density.

Meteor: A small celestial body that enters Earth's atmosphere and burns up due to friction with air, creating a visible streak of light in the sky.