Stratosphere

Definition

The stratosphere is the second layer of Earth's atmosphere, situated above the troposphere and below the mesosphere, extending from about 10 to 50 kilometers above the Earth's surface. This layer is characterized by a temperature inversion, where temperature increases with altitude due to the presence of ozone, which absorbs harmful ultraviolet radiation from the sun. The stratosphere plays a crucial role in atmospheric geochemistry as it contains the ozone layer, which protects living organisms from excessive UV radiation and influences atmospheric composition.

5 Must Know Facts For Your Next Test

1. The stratosphere is critical for protecting life on Earth as it contains the ozone layer, which absorbs around 98% of the sun's harmful UV radiation.
2. Temperature in the stratosphere increases with altitude due to ozone's absorption of solar energy, contrasting with the cooling trend observed in the troposphere.
3. Aircraft typically fly within the lower stratosphere to avoid turbulence found in the troposphere and take advantage of more stable atmospheric conditions.
4. The stratosphere has relatively low humidity and fewer clouds compared to the troposphere, resulting in clearer skies at this altitude.
5. Stratospheric chemistry is significantly impacted by human activities, particularly the release of chlorofluorocarbons (CFCs), which have led to ozone depletion.

Review Questions

• How does the temperature profile of the stratosphere differ from that of the troposphere, and why is this difference significant for atmospheric dynamics?
  • In the troposphere, temperature decreases with increasing altitude, while in the stratosphere, temperature increases with altitude due to the absorption of UV radiation by ozone. This inversion creates a stable atmospheric layer in the stratosphere that prevents vertical mixing and leads to clearer skies compared to the turbulent weather patterns found in the troposphere. Understanding this difference is crucial for predicting weather and studying climate change impacts.
• Discuss the role of the ozone layer within the stratosphere and its importance for life on Earth.
  • The ozone layer, located in the stratosphere, plays a vital role by absorbing approximately 98% of harmful ultraviolet (UV) radiation from the sun. This protection is crucial for preventing skin cancers and other health issues in humans as well as protecting ecosystems and wildlife. The depletion of this ozone layer due to pollutants like CFCs has raised significant environmental concerns and necessitated international efforts for its restoration.
• Evaluate how human activities have impacted stratospheric chemistry and discuss potential long-term consequences.
  • Human activities, particularly through the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances, have significantly altered stratospheric chemistry, leading to thinning of the ozone layer. These changes can increase UV radiation reaching Earth's surface, which may result in higher incidences of skin cancer, compromised ecosystems, and disruptions in food chains. Long-term consequences include potential shifts in climate patterns due to changes in atmospheric heating and cooling processes associated with altered ozone levels.

Related terms

Ozone Layer: A region within the stratosphere that contains a high concentration of ozone (O₃) molecules, essential for absorbing and filtering out harmful ultraviolet (UV) radiation from the sun.

Tropopause: The boundary between the troposphere and stratosphere, marking a transition in temperature and pressure, generally occurring at an altitude of around 10 kilometers.

Mesosphere: The layer of Earth's atmosphere situated above the stratosphere and below the thermosphere, extending from about 50 to 85 kilometers in altitude.