Normal Lapse rate in troposphere is :

Question

Accepted Answer

The normal lapse rate in the troposphere is the rate at which temperature decreases with an increase in altitude. The correct answer is Option 3: 6.5°C per 1000 meters. Let's explore why this is the correct choice and why the other options are incorrect.

1. **Explanation for Option 3 (6.5°C Per 1000 meters):**
   - The troposphere is the lowest layer of Earth's atmosphere, where most of the weather phenomena occur. In this layer, the temperature generally decreases with altitude. The average rate of this temperature decrease is known as the "normal lapse rate."
   - The normal lapse rate is approximately 6.5°C per 1000 meters (or 3.6°F per 1000 feet). This value is derived from extensive meteorological observations and is considered a standard reference in atmospheric science.
   - This lapse rate is an average value, as actual lapse rates can vary due to local weather conditions, humidity, and other factors. However, 6.5°C per 1000 meters is widely accepted as the standard average.

2. **Explanation for why other options are incorrect:**
   - **Option 1 (6°C Per 1000 meters):** While close to the correct value, 6°C per 1000 meters is not the standard average lapse rate. The accepted average is slightly higher at 6.5°C per 1000 meters.
   - **Option 2 (8°C Per 1000 meters):** This value is higher than the standard average lapse rate. An 8°C decrease per 1000 meters would indicate a steeper temperature gradient than what is typically observed in the troposphere.
   - **Option 4 (5.5°C Per 1000 meters):** This value is lower than the standard average lapse rate. A 5.5°C decrease per 1000 meters would suggest a more gradual temperature decline than the average observed in the troposphere.

In conclusion, Option 3 is the correct answer because it accurately reflects the widely accepted average normal lapse rate in the troposphere, which is 6.5°C per 1000 meters. This value is based on extensive meteorological data and is used as a standard reference in atmospheric studies.