Air Masses & Fronts

Objective• You will use air masses,

fronts and pressure in order to explain how weather changes and conditions occur.

Drill• What is the method of heat

transfer that is used throughout the atmosphere to cause clouds and essentially weather?

What is Air Pressure

• Air weight that varies over Earth’s surface–Warmer air is less dense and exerts less

pressure– Cooler air is more dense and exerts

more pressure

What is Air Pressure?

High Pressure• When cooler air sinks

and is warmed, the air can hold more moisture

• This usually means sunny skies

• Winds tend to move clockwise around a high

Low Pressure

What is Air Pressure?

Low Pressure• When warm air rises and

is cooled, the air can not hold as much moisture

• Often, these areas are associated with precipitation and stormy weather

• Winds tend to move counter clockwise around the low

Low Pressure

What does this mean for us?

These highs and lows move or less along the jet stream and bring us our weather changes

What is an Air Mass?An air mass is a large body of air whose

temperature and moisture are fairly similar at a given altitude; properties like the part of Earth’s

surface over which it formed.

Website

Click on Task 6

Use these websites to Identify types of Air

Masses!

Closure:

• Explain how air masses, air pressure, and fronts are responsible for our weather. ( use all 3 terms in your response and terms you used throughout the activity) (5 sentences).