Stratosphere

Definition

The stratosphere is the second layer of Earth's atmosphere, located above the troposphere and below the mesosphere, extending from about 10 to 50 kilometers above sea level. This layer is crucial for stratospheric ozone chemistry, as it contains the ozone layer, which absorbs and scatters the solar ultraviolet radiation, protecting living organisms on Earth from harmful UV rays.

5 Must Know Facts For Your Next Test

1. The stratosphere is stable and stratified, meaning that it has a temperature inversion where temperatures increase with altitude, unlike the troposphere where they decrease.
2. The presence of ozone in the stratosphere plays a vital role in protecting life on Earth by absorbing approximately 97-99% of the sun's harmful UV radiation.
3. Human-made chemicals, particularly chlorofluorocarbons (CFCs), have contributed to ozone depletion in the stratosphere, leading to international efforts like the Montreal Protocol to reduce their use.
4. The stratosphere also influences weather patterns and climate as it interacts with lower layers of the atmosphere and can affect phenomena such as jet streams.
5. Understanding stratospheric ozone chemistry is essential for predicting changes in UV radiation exposure and its potential impacts on human health and ecosystems.

Review Questions

• How does the structure of the stratosphere contribute to its role in ozone chemistry?
  • The stratosphere's structure, characterized by a temperature inversion where temperature increases with altitude, allows for a stable environment that supports the formation and maintenance of the ozone layer. This stability minimizes vertical mixing with the troposphere below, allowing ozone molecules to accumulate. As a result, this layer efficiently absorbs harmful UV radiation from the sun, which is crucial for protecting life on Earth.
• Discuss the impact of human activities on stratospheric ozone levels and the measures taken to address these changes.
  • Human activities, particularly the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances, have significantly impacted stratospheric ozone levels by causing its depletion. The destruction of ozone molecules results in increased UV radiation reaching Earth's surface, leading to potential health risks like skin cancer and ecological damage. In response, global efforts such as the Montreal Protocol were established to phase out CFCs and promote alternatives, successfully leading to signs of recovery in the ozone layer.
• Evaluate how changes in stratospheric ozone concentrations can influence global climate patterns.
  • Changes in stratospheric ozone concentrations can have significant effects on global climate patterns by altering temperature distributions and atmospheric circulation. For instance, reduced ozone levels may lead to increased UV radiation reaching the surface, which can warm certain regions while cooling others. This imbalance can disrupt weather systems and jet streams, potentially impacting precipitation patterns and contributing to extreme weather events. Consequently, understanding these interactions is crucial for predicting future climate scenarios and developing strategies for climate adaptation.

Related terms

Ozone Layer: A region within the stratosphere that contains a high concentration of ozone (O₃) molecules, which absorb most of the sun's harmful ultraviolet radiation.

Troposphere:

The lowest layer of Earth's atmosphere, extending from the surface to about 10 kilometers, where most weather events occur and where humans live.

Mesosphere: The layer of Earth's atmosphere located above the stratosphere, extending from about 50 to 85 kilometers, characterized by decreasing temperatures and where most meteors burn up upon entering the atmosphere.