Chapter 4

What would the saturated adiabatic lapse rate be in a situation where all the water vapor was removed from the air and no other moisture was available to evaporate into the air?

10C/km

You are in the middle of a fog bank. The temperature is 10 degrees Celsius, and the saturation vapor pressure for that temperature is 12 mb. What do you think the vapor pressure of the air around you is equal to, in millibars?

12.0

You see a cloud in the sky that doesn't look exactly like any of the examples above. But you notice that it has a lumpy shape to it, and there is rain falling out of it. What kind of cloud is it?

Cumulonimbus

True or False: warmer air can hold more water vapor than colder air because there is more space between the air molecules for water to fit into.

False

An inversion with a shallow layer of below-freezing air at and just above the ground

Freezing rain

When precipitation falls into air that is unsaturated, what happens to the temperature of the air? PLAY WITH THE APPLET!

Goes down

What happens to the elevation of the cloud base, as the surface relative humidity is reduced in the applet below? Is the cloud base higher, or is it lower, when the RH is reduced?

Higher

Why doesn't the applet above let the dew point be higher than the temperature? Choose ALL correct answers.

Outside of microscopic regions the dew point cannot be higher than the temperature. Outside of microscopic regions the relative humidity cannot be higher than 100%.

Above-freezing temperatures all the way to the ground.

Rain

An inversion with a deeper layer of below-freezing air at and above the ground

Sleet

When precipitation falls into dry (unsaturated) air, what happens to the difference between the air temperature and the dew-point temperature? What does this mean about the change in relative humidity (RH)? PLAY WITH THE APPLET!

Smaller difference between T and Td and increased RH

Below-freezing temperatures all the way to the ground

Snow

What shape of ice crystal do you get if the precipitation particle forms at the top part of the cloud and stays there? (Just keep clicking on the applet.)

Tall columns

Which of the situations below would be examples of high relative humidity (e.g., RH > 80% or so)? More than one answer may be correct.

Temperature = 10F and dew point = 10F Temperature = 50F and dew point = 49F