Hello, how are you doing

could you please help me with a question about my weather class, which is giving me a hard time

 

the question is

Why there is more moisture over a desert than over the poles?

 

our professor just told us that the reason wasn't because the atmosphere

can "hold" more moisture at higher temperatures (which exist over the desert) than the colder temperatures found over the polar regions.

 

 

thank you.

The obvious critical factor is the vapor pressure, which is much lower at -40C (0.13 mmHg) than at 40C (55.35 mmHg). Raising water-saturated air from -40C to 40C without adding any moisture results in 0.24% relative humidity. The humidity is low in the desert, but not that low (relative humidity is in the low teens or single digits).

 

Perhaps the instructor was meaning relative humidity and used some words that made you think absolute humidity.

DH, thanks a lot for the help.