What air mass has the driest air?

Air has density and pressure because it has mass.Even though it doesn't seem like air has any mass.Yes,air has mass.

Yes, it occupies space.

mass = density * volume. Air density is p/RT, where R is the gas constant for air (287 J/kg-K), T is the absolute temperature and p is the pressure, equal to 101325 Pa at sea level. At sea level and...

Yes. Cold air masses have higher density, because the molecules are closer together. That makes them have higher pressure because there is more mass per unit volume pressing down. The molecules are...

It has more molicules....