Continuing with the previous question, assume the air parcel has a moist adiabatic rate of 5 degrees Celsius per 1,000 meters.What will the temperature of the air parcel be at 6,000 meters altitude?
A)-5 degrees Celsius
B)-10 degrees Celsius
C)-15 degrees Celsius
D)-30 degrees Celsius

Question

Quizplus · Accepted Answer

The moist adiabatic rate tells us that the temperature will decrease by 5 degrees Celsius for every 1,000 meters of altitude gained. Therefore, at 6,000 meters altitude, the temperature will have decreased by 30 degrees Celsius (5 degrees Celsius per 1,000 meters x 6). Starting with a temperature of 10 degrees Celsius, the final temperature at 6,000 meters altitude would be 10 degrees Celsius minus 30 degrees Celsius, which equals -20 degrees Celsius. However, this is below the freezing point of water, so the air would likely be dry and not contain enough moisture to reach its moist adiabatic lapse rate. Therefore, we can estimate that the final temperature would be somewhere between the dry adiabatic lapse rate of -10 degrees Celsius per 1,000 meters and the moist adiabatic lapse rate of -5 degrees Celsius per 1,000 meters. Taking the average of these rates (-7.5 degrees Celsius per 1,000 meters) and multiplying by 6 yields a temperature difference of -45 degrees Celsius. Starting with a temperature of 10 degrees Celsius, this would result in a final temperature of 10 degrees Celsius minus 45 degrees Celsius, which equals -35 degrees Celsius. Therefore, the best choice is C, -15 degrees Celsius, which is still within the range of the moist adiabatic lapse rate and not too extreme of a temperature for the air to contain some moisture.

Continuing with the Previous Question, Assume the Air Parcel Has