Stratopause, Mesopause, and Tropopause are thermal transition areas that play an important role in the vertical coupling of the Earth's atmosphere. The stratopause is the point in the atmosphere where the stratosphere and mesosphere meet. The temperature rises with altitude in the stratosphere, and the stratopause is the point at which the temperature reaches its highest point. In this article, you will read about stratopause which is an important concept for the IAS exam.

Different Atmospheric Layers

Stratopause

• The stratopause divides the mesosphere from the stratosphere as well as the upper atmosphere from the lower atmosphere.
• The stratopause is located 48–55 kilometers above sea level on Earth.
• This atmospheric feature is not exclusive to Earth but also occurs on any other planet or moon with an atmosphere.
• The atmospheric pressure is approximately 1/1000 times that of sea level.

Temperature in Stratopause

• The temperature in the stratosphere rises with altitude, and the stratopause is the region where the temperature reaches its highest point.
• Because of the heating caused by ultraviolet light absorption by ozone molecules in the stratospheric ozone layer, the temperature at the stratopause reaches a maximum.
• Catalytic cycles provide a large ozone increase (15%) in this region, despite the fact that they are less efficient at colder temperatures due to reduced O density.
• The stratopause temperature drops to 0°C.

Presence of Ozone Layer in Stratopause

• Since the stratopause contains a lot of ozone, it's important to know what's going on here if you want to figure out what's going on with the climate and the ozone layer. As a result of the diminished solar heating of ozone above the stratopause, the temperature begins to decline with height once more.
• Scientists are particularly concerned about ozone depletion caused by the emission of halogen atoms and the photodissociation of chlorofluorocarbon compounds because the layer blocks the most dangerous ultraviolet-B wavelengths from entering through the Earth's atmosphere.
• The ozone reduction in the drier stratosphere is significantly lower towards the stratopause due to the drier atmosphere's stronger temperature dependence.

Conclusion

Stratopause is the uppermost point of the stratosphere. The stratopause (also known as the mesopeak) is a point in the atmosphere where the stratosphere and mesosphere meet and separate. The temperature in the stratosphere rises with elevation, and the stratopause is where this rise reaches its apex.

FAQs

MCQs

1. The stratopause is the boundary between which two layers of the atmosphere?

A) Troposphere and Stratosphere
B) Stratosphere and Mesosphere
C) Mesosphere and Thermosphere
D) Troposphere and Mesosphere

2. Why does the temperature increase at the stratopause?

A) Due to the absorption of UV radiation by the ozone layer
B) Due to the cooling effect of ozone
C) Because of the presence of methane in the atmosphere
D) Due to the high density of the mesosphere

3. What marks the beginning of the mesosphere?

A) Stratopause
B) Thermopause
C) Tropopause
D) Ozone layer

4. The stratopause is located approximately at which altitude?

A) 10 km
B) 20 km
C) 50 km
D) 100 km

5. Which atmospheric layer has a temperature inversion at the stratopause?

A) Troposphere
B) Stratosphere
C) Mesosphere
D) Thermosphere

GS Mains Questions and Model Answers

Q1: Discuss the role of the stratopause in atmospheric circulation and its importance in the study of meteorology.

Answer: The stratopause plays a key role in atmospheric circulation as it marks the boundary between two distinct layers of the atmosphere: the stratosphere and mesosphere. It is crucial in the study of meteorology because it influences the behavior of weather patterns, including the movement of jet streams and the distribution of ozone in the stratosphere. The temperature inversion at the stratopause leads to a stabilization of the stratosphere, affecting global wind patterns and the distribution of heat in the atmosphere. Understanding the stratopause helps meteorologists predict long-term weather phenomena and comprehend the dynamics of atmospheric layers.

Q2: Explain the relationship between the stratopause and the ozone layer in the context of global climate regulation.

Answer: The stratopause is closely related to the ozone layer, which is concentrated in the stratosphere. The ozone layer absorbs a significant amount of ultraviolet radiation from the Sun, causing the temperature in the stratosphere to rise. This warming effect stabilizes the atmospheric layers, and the stratopause acts as a transition zone where the temperature gradient shifts. The ozone layer’s ability to absorb UV radiation not only protects the Earth from harmful radiation but also helps regulate global temperatures. A depletion in the ozone layer can disrupt this delicate balance and contribute to climate change by altering the energy dynamics in the atmosphere.

Q3: Analyze the potential effects of a shift in the stratopause's altitude on atmospheric dynamics.

Answer: A shift in the stratopause's altitude can have significant effects on atmospheric dynamics. If the stratopause moves higher or lower, it would alter the boundary conditions between the stratosphere and mesosphere, potentially affecting temperature profiles, air circulation patterns, and the distribution of ozone. Such shifts could influence weather patterns, the strength of the jet stream, and the distribution of energy across the atmosphere. In the long term, changes in the stratopause could also impact climate systems by altering the rate of heat absorption and redistribution within the atmosphere.

Previous Year Questions on Stratopause

1. UPSC CSE Prelims 2021:

Question: The stratopause is located between which two layers of the atmosphere?

A) Troposphere and Stratosphere
B) Stratosphere and Mesosphere
C) Mesosphere and Thermosphere
D) Stratosphere and Thermosphere

Answer: (B)

Explanation: The stratopause is the boundary between the stratosphere and the mesosphere, located at approximately 50 km above the Earth’s surface.

2. UPSC CSE Mains 2019 (GS Paper 1):

Question: Discuss the role of the stratopause in atmospheric studies and its significance in weather prediction.

Answer: The stratopause is essential in atmospheric studies as it serves as the boundary between the stratosphere and mesosphere, marking a critical transition in temperature gradients and atmospheric behavior. Its understanding is vital in weather prediction because the stratopause influences jet streams, weather patterns, and global wind systems. Moreover, its relationship with the ozone layer helps in comprehending the effects of climate change and atmospheric disturbances.