Stratosphere

Definition

The stratosphere is the second layer of Earth's atmosphere, situated above the troposphere and extending from about 10 to 50 kilometers above the Earth's surface. It is characterized by a temperature increase with altitude and contains the ozone layer, which plays a crucial role in absorbing harmful ultraviolet radiation from the sun.

5 Must Know Facts For Your Next Test

1. The stratosphere contains approximately 19% of the atmosphere's total mass and is much more stable compared to the turbulent troposphere below it.
2. The temperature in the stratosphere increases with altitude due to the absorption of ultraviolet radiation by the ozone layer, contrasting with the troposphere where temperature decreases with height.
3. Commercial jet aircraft typically fly in the lower part of the stratosphere, taking advantage of its stability and reduced turbulence to enhance fuel efficiency.
4. The presence of the ozone layer in the stratosphere is vital for protecting living organisms from UV radiation, as increased exposure can lead to health issues such as skin cancer and cataracts.
5. Human activities, such as the release of chlorofluorocarbons (CFCs), have contributed to ozone depletion in the stratosphere, leading to international agreements like the Montreal Protocol aimed at protecting this critical layer.

Review Questions

• What role does the ozone layer within the stratosphere play in protecting life on Earth?
  • The ozone layer, located in the stratosphere, plays a vital role in safeguarding life on Earth by absorbing most of the sun's harmful ultraviolet (UV) radiation. Without this protective layer, increased UV exposure could lead to serious health problems, including skin cancer and cataracts in humans, as well as detrimental effects on various ecosystems. This underscores why maintaining the integrity of the ozone layer is crucial for environmental and public health.
• How does temperature change with altitude in the stratosphere, and what causes this phenomenon?
  • In the stratosphere, temperature increases with altitude, a phenomenon known as temperature inversion. This occurs because the ozone layer absorbs ultraviolet radiation from the sun, heating up this region of the atmosphere. In contrast to the troposphere below, where temperatures decrease with height due to a lack of heating from solar radiation, this unique temperature gradient in the stratosphere contributes to its stability and limits vertical mixing.
• Evaluate the impact of human activities on the stratosphere and discuss how they have led to changes in its composition.
  • Human activities, particularly the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances, have significantly impacted the composition of the stratosphere by contributing to ozone layer depletion. The thinning of this protective layer has resulted in increased UV radiation reaching Earth's surface, leading to serious environmental and health consequences. The global response to this issue, including international agreements like the Montreal Protocol, highlights efforts made to reduce CFC emissions and promote alternatives, reflecting a broader recognition of our responsibility to protect atmospheric layers crucial for life.

Related terms

Ozone Layer: A region within the stratosphere that contains a high concentration of ozone (O₃) molecules, essential for protecting life on Earth by absorbing most of the sun's harmful ultraviolet radiation.

Tropopause: The boundary layer between the troposphere and the stratosphere, where the temperature transition occurs and marks the limit of weather phenomena.

Jet Stream: Fast-flowing air currents found within the stratosphere that significantly influence weather patterns and climate.