South Rim Trailhead (6,800 ft) 84°F
3-mile resthouse (4,900 ft)
River resthouse (2,500 ft)
Geog 1401 Assignment 2: Lapse Rates
Name:
1.
Match each of the following lapse rates with the appropriate condition for which they should be used.
Each answer is used only once.
a.
Normal/environmental lapse rate (NLR/ELR; 3.5°F/1,000 ft)
b.
Dry adiabatic lapse rate (DALR; 5.5°F/1,000 ft)
c.
Wet adiabatic lapse rate (WALR; ~3.0-3.2°F/1,000 ft)
_A__An air parcel is unstable and is rising. It is at or below the dew point temperature, meaning its
relative humidity is 100%.
_B__The air is stable and not rising or descending.
_C__An air parcel is unstable and is rising. It is above the dew point temperature, meaning its relative
humidity is less than 100%.
2.
Using the Grand Canyon as an example from class, and assuming the air is
stable
and not rising on a
given day, what is the temperature at the following places if it is 84°F at the South Rim Trailhead that is
6,800 feet in elevation?
You can round to one decimal place for your answers. Hint: Does the air warm
up or cool down as you go down in elevation?
3-mile resthouse at 4,900 feet ___95__ °F
River resthouse at 2,500 feet ___108__ °F
How much did the temperature change from the
South Rim Trailhead to the River resthouse?
___94__ °F
3.
Fill in the temperatures for the following diagram using the information provided. The air is
unstable
around Galveston Island on a warm summer day, leading the air parcel to rise. When the parcel starts
at 0 feet of elevation it is 94°F. It reaches the dew point boundary at 4,000 feet of elevation. It reaches a
final elevation of 8,000 feet.
Hints: Think about when you use the DALR and the WALR; use a WALR of
3.0°F/1,000 ft; is the air parcel warming or cooling as it increases in elevation and expands?
__60_____
_°F
8,000 ft
__94__°F
___72_____°
F
0 ft
4,000 ft
