Question

Consider the following statements:

1. The temperature lapse rate in the troposphere is approximately 1°C per 165 meters.

2. The temperature in the stratosphere increases with altitude.

Which of the above is/are correct?

• A. 1 only
• B. 2 only
• C. Both 1 and 2
• D. Neither 1 nor 2

Answer 1

Answer:

C. Both 1 and 2

• Correct Answer: Option C) Both 1 and 2

• Statement 1: The temperature lapse rate in the troposphere is approximately 1°C per 165 meters.

• This statement is correct. The normal environmental lapse rate (also called the average lapse rate) in the troposphere is approximately 6.5°C per 1000 meters, which translates to about 1°C per 154 meters. The given figure of 165 meters is very close to this standard value and falls within the acceptable range. This lapse rate occurs because air temperature generally decreases with altitude in the troposphere due to decreasing atmospheric pressure and the cooling effect of expansion.

• Statement 2: The temperature in the stratosphere increases with altitude.This statement is also correct. Unlike the troposphere, the stratosphere exhibits a temperature inversion where temperature actually increases with altitude. This phenomenon occurs due to the presence of the ozone layer (ozone concentration) in the stratosphere. Ozone absorbs ultraviolet radiation from the sun, converting it to heat energy. As we move higher in the stratosphere, the concentration of ozone increases, leading to higher temperatures. The temperature can rise from about -60°C at the tropopause to around 0°C at the stratopause.

• Key Points:

• The troposphere shows decreasing temperature with altitude (negative lapse rate)

• The stratosphere shows increasing temperature with altitude (temperature inversion)

• This difference is due to different heating mechanisms in each layer

• The ozone layer is the primary reason for stratospheric warming