Stratosphere

Definition

The stratosphere is the second major layer of Earth's atmosphere, located above the troposphere and below the mesosphere, extending from about 10 to 50 kilometers above the Earth's surface. This layer is crucial for atmospheric chemistry, particularly because it contains the ozone layer, which absorbs and scatters ultraviolet solar radiation, protecting living organisms on Earth.

5 Must Know Facts For Your Next Test

1. The stratosphere is characterized by a temperature inversion, where temperatures rise with altitude due to the absorption of UV radiation by ozone.
2. Commercial jet aircraft typically fly within the lower stratosphere, as it provides a more stable environment with fewer weather disturbances than the troposphere.
3. The presence of ozone in the stratosphere is vital for life on Earth, as it protects ecosystems by filtering out harmful UV radiation from sunlight.
4. Human-made chemicals, such as chlorofluorocarbons (CFCs), have historically damaged the ozone layer, leading to international agreements like the Montreal Protocol aimed at its protection.
5. Stratospheric processes influence long-term climate patterns and can affect weather systems through interactions with the troposphere.

Review Questions

• How does the presence of ozone in the stratosphere influence life on Earth?
  • Ozone in the stratosphere plays a critical role in protecting life on Earth by absorbing and scattering harmful ultraviolet (UV) radiation from the Sun. Without this protective layer, increased UV exposure would lead to higher rates of skin cancer, cataracts, and other health issues in humans, as well as detrimental effects on wildlife and ecosystems. The ozone layer thus acts as a shield that allows life to thrive by reducing harmful radiation levels reaching the surface.
• What are the key differences between the troposphere and stratosphere in terms of temperature behavior and atmospheric composition?
  • The primary difference between the troposphere and stratosphere lies in their temperature behavior; in the troposphere, temperature decreases with altitude, while in the stratosphere, temperature increases due to ozone absorption of UV radiation. Additionally, the composition varies: the troposphere contains water vapor and is where weather phenomena occur, whereas the stratosphere has a more stable composition with a higher concentration of ozone but less water vapor. These differences are fundamental in understanding atmospheric dynamics and climate.
• Evaluate the implications of human activities on the stratospheric ozone layer and discuss how these changes might affect global climate patterns.
  • Human activities, particularly the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances, have significantly harmed the stratospheric ozone layer. The depletion of ozone increases UV radiation reaching Earth’s surface, which can lead to negative impacts on human health, ecosystems, and agriculture. Furthermore, changes in ozone concentrations can affect atmospheric circulation patterns and climate systems globally, leading to shifts in weather patterns and potentially exacerbating climate change effects.

Related terms

Ozone Layer: A region within the stratosphere that contains a high concentration of ozone (O₃) molecules, crucial for absorbing harmful ultraviolet radiation from the Sun.

Tropopause: The boundary layer that separates the troposphere from the stratosphere, marking a transition where temperature stops decreasing with altitude and begins to increase.

Jet Stream: A fast-flowing air current found in the upper levels of the atmosphere, primarily in the stratosphere, which influences weather patterns and systems.