Stratosphere

Definition

The stratosphere is the second major layer of Earth's atmosphere, located above the troposphere and extending from about 10 to 50 kilometers (6 to 31 miles) above sea level. This layer is crucial for regulating the planet's climate and protecting life on Earth due to its ozone layer, which absorbs and scatters ultraviolet solar radiation.

5 Must Know Facts For Your Next Test

1. The temperature in the stratosphere increases with altitude, which is opposite to the temperature trend in the troposphere, leading to a stable atmosphere that helps minimize weather disturbances.
2. The ozone layer within the stratosphere is crucial for absorbing approximately 97-99% of the sun's harmful UV radiation, significantly reducing its impact on living organisms.
3. The stratosphere contains the jet streams, which are significant for weather forecasting as they influence storm patterns and help determine climate conditions in different regions.
4. Commercial airlines typically fly within the lower stratosphere to avoid turbulence found in the troposphere, making air travel smoother and more efficient.
5. Human activities, such as the use of chlorofluorocarbons (CFCs), have led to stratospheric ozone depletion, prompting global efforts like the Montreal Protocol to protect this essential layer.

Review Questions

• How does the structure of the stratosphere contribute to its stability compared to the troposphere?
  • The stratosphere is more stable than the troposphere due to its temperature profile, which increases with altitude. This temperature inversion prevents vertical mixing, allowing air to remain stratified. As a result, weather systems are generally less turbulent in this layer, contributing to a more stable atmospheric environment that supports long-distance travel and aviation.
• What role does the ozone layer play within the stratosphere regarding global climate and living organisms?
  • The ozone layer serves as a protective shield within the stratosphere by absorbing about 97-99% of the sun's harmful ultraviolet radiation. This absorption process is critical for preventing skin cancer and other health issues in humans and animals, as well as protecting ecosystems from UV-induced damage. The presence of ozone directly influences global climate by regulating energy transfer between the sun and Earth.
• Evaluate how human activities have impacted the stratosphere and what measures have been taken to address these effects.
  • Human activities, particularly the release of chlorofluorocarbons (CFCs), have led to significant depletion of ozone in the stratosphere, resulting in increased UV radiation reaching Earth's surface. This has raised concerns about public health and environmental impacts. In response, international agreements like the Montreal Protocol were established to phase out CFCs and other ozone-depleting substances, showcasing global cooperation aimed at restoring and protecting this vital atmospheric layer.

Related terms

Troposphere:

The lowest layer of Earth's atmosphere, where weather occurs and where most of the mass of the atmosphere is found.

Ozone Layer: A region within the stratosphere that contains a high concentration of ozone (O₃) and plays a vital role in protecting living organisms from harmful ultraviolet radiation.

Jet Stream: Fast-flowing air currents located in the upper levels of the atmosphere, often found at the boundaries between the troposphere and stratosphere, influencing weather patterns.