Air Mass Basics
What is an air mass?
A large section of the troposphere with uniform temperature and moisture.
Which air mass has more moisture—continental or maritime?
Maritime
What kind of clouds form in stable air?
Stratus.
What is a front?
The boundary between two air masses.
What kind of weather does a squall bring?
Sudden gusty winds and heavy rain or hail.
What determines the characteristics of an air mass?
The surface over which it forms.
What process must occur for a cloud to form?
Cooling air to its dew point.
What kind of clouds form in unstable air?
Cumulus
What happens when a cold front passes?
Temperature drops and skies clear after heavy rain or storms.
What is a trough?
An elongated area of low pressure causing clouds and showers.
What type of air mass forms over land?
Continental – dry.
Name one way air can cool to form clouds.
Contact with a cooler surface / advection / expansion by lifting.
Stable air leads to what type of visibility?
Poor visibility.
What type of clouds form along a warm front?
Cirrus → Altostratus → Nimbostratus → Stratus.
What does a dry line separate?
Moist and dry air masses.
What type forms over water?
Maritime – moist.
In the “Cloud in a Jar” activity, what represents condensation nuclei?
Smoke.
Unstable air often results in what type of weather?
Turbulence, good visibility, and showers.
What kind of front occurs when neither air mass advances?
Stationary front.
What weather is associated with a tropical wave?
Showers and thunderstorms, possibly hurricanes.
What are the two main classifications of temperature for air masses?
Cold (Arctic/Polar) and Warm (Tropical).
Why is ice placed on top of the jar in the cloud experiment?
To cool the air and reach the dew point, forming a cloud.
Why does warm air tend to be stable?
It resists vertical movement and rises slowly.
What front forms when a cold front overtakes a warm front?
Occluded front.
After a cold front passes, what weather conditions typically follow?
Cooler temperatures and clear skies.