Question

A parcel of unsaturated air at 500 meters above sea level has a temperature of 20°C. What will the parcel's temperature be if it rises to an altitude of 1500 meters, remaining unsaturated all the way to this altitude?

(a) 10°C

(b) 15°C

(c) 20°C

(d) 25°C

Answer 1

The parcel's temperature will be 10°C when it reaches an altitude of 1500 meters.

Step-by-step explanation:

When a parcel of unsaturated air rises in the atmosphere, it expands and cools adiabatically at a rate of approximately 1°C per 100 meters. Since the parcel is rising from 500 meters to 1500 meters, it will cool by 1°C per 100 meters multiplied by 10 (the difference in altitude in hundreds of meters) which equals 10°C. Therefore, the parcel's temperature will be 20°C - 10°C = 10°C when it reaches an altitude of 1500 meters.