Air Masses

The boundary where unlike air masses meet but do not mix.

• air mass

• jet stream

• front

• cyclone

• anticyclone

A swirling center of low air pressure.

• air mass

• jet stream

• front

• cyclone

• anticyclone

A huge body of air that has similar temperature, humidity, and air pressure at any given height.

• air mass

• jet stream

• front

• cyclone

• anticyclone

A high-pressure center of dry air.

• air mass

• jet stream

• front

• cyclone

• anticyclone

Band of high-speed winds about 10 kilometers above Earth’s surface.

• air mass

• jet stream

• front

• cyclone

• anticyclone

Keli learned that an air mass is a very large body of air with similar temperatures, humidity, and pressure, and that air masses are constantly in motion. She knows the air masses change, depending on the temperature and moisture content of the region where they form. She looked up more information about what makes them move. What are the major causes for moving air masses in North America? Choose the two that apply.

• changing humidity

• low temperatures

• jet stream

• prevailing westerlies

When a warm air mass is caught between two cold fronts, the result is a(n) ______________ front.

• occluded

• warm

• cold

• stationary

When a cold air mass runs into a warm air mass, the result is a(n) _____________ front.

• occluded

• warm

• cold

• stationary

When a fast-moving warm air mass overtakes a slower-moving cold air mass, the result is a(n) _____________ front.

• occluded

• warm

• cold

• stationary

When a warm air mass runs into a cold air mass but neither one can move the other, the result is a(n) _____________ front.

• occluded

• warm

• cold

• stationary