4th grade-ch. 6 lesson 3 what are air masses

Ch. 6Lesson 3

What are air masses?

air mass•huge body of air that has almost same temp. & humidity (amount of water vapor in air)

air mass•cause most weather

air mass•forms over large areas of land or water

Type of air mass Where it forms

Cool air mass polar areas

Warm air mass tropical area

Greater humidity over water

Less humidity over land

What characteristics would an air mass that formed here

have?

What characteristics would an air mass that formed here have?

front• area where 2 air

masses meet

front• 2 types:

1. cold front- move faster

2. warm front- move slower

Cold air mass & a warm air mass meeting at a front.

Air Masses and Fronts: How Weather Moves From One Place to Another [03:24]

How clouds form:

1.Sun’s energy warms water

2.Heated water evaporates

3.Air rises & cools

4.Water vapor become tiny water droplets & ice crystals

3 main types of clouds

cumulus stratus cirrus

cumulus clouds

•fair weather

cumulus clouds

•look like fluffy, rounded piles of cotton

strstratatus cloudsus clouds• form in flatat layers close to

Earth’s surface

cirrus clouds• feathery clouds • form high in atmosphere

cirrus clouds Sometimes

called “mare’s tails”

Song: Clouds Are Cool [02:45]

•Cloud matching game

form only at high levels

cirrus clouds

Cumulus clouds

•look like fluffy, rounded piles of cotton

Cirrus clouds Sometimes called “mare’s tails”

strstratatus cloudsus clouds• form in flatat layers

cirrus clouds• feathery clouds • form high in atmosphere

cumulus clouds•fair weather