The dry adiabatic lapse rate (DALR) is approximately 9.8°C per kilometer (or 1°C per 100 meters).
To calculate how much an air parcel cools as it descends from 2500 m to 1000 m:
-
Calculate the change in altitude:
- 2500 m - 1000 m = 1500 m
-
Convert the change in altitude to kilometers:
- 1500 m = 1.5 km
-
Apply the dry adiabatic lapse rate:
- Cooling = 1.5 km × 9.8°C/km = 14.7°C
Since the options provided are:
- 15°C
- 6°C
- 10°C
- None of the options apply
- 3°C
The closest choice is 15°C.