Science: Fronts and masses

What is an air mass?

A large body of air with properties similar to the area over which it formed.

How can you determine the type of air mass?

Temperature & Humidity

Where do air masses form?

Over land (continental) or water (Maritime)

Maritime:

**Forms over water; wet**

**Continental:**

**Forms over land; dry**

Polar:

**Forms over poles; cold**

Arctic:

Forms in the arctic

 **What is a front?**

An area where 2 air masses meet or collide

What is the area where two air masses collide called?

A boundry

What happens when a warm air mass collides with a cold air mass?

It creates condensation

The amount of condensation when air masses collide is dependent on the air masses:

Temperature, humidity, and density

Cold front:

Cold mass pushes under warm. Warm rises

Cold fronts bring:

The warm air from the warm front condensates. Causing clouds leading to thunderstorms.

Warm Front:

Warm front moves over cold

Warm fronts bring:

The warm air condensates into clouds. Bring gentle rain or light snow, and mild, warm weather.

Stationary front:

When neither mass has the energy to move, so they “stand still”.

Stationary fronts bring:

Clouds, rain, and fog occur

Occluded front:

When warm air gets caught between to cold air masses. The warm air rises and the cold masses meet.

Occluded fronts bring:

The temperature drops as the cold masses meet after evaporating the warm.

Do air masses mix?

No

What type of front is associated with high-pressure systems?

Warm fronts. The air is pushed closer to the surface.

What type of pressure system indicates calm, clear weather?

High pressure systems usually indicate calm, clearer weather. This is because the air is moving downward as opposed to having rising air that cools into clouds.

**What type of pressure system happens when a cold front moves through a warm front?**

Cold air pushes its way through the warmer and lifts the warm air. Because air is lifted is called a low-pressure system.

Which is more dense, cold air or warm?

Cold air is more dense

**What type of pressure system causes severe rainfall?**

Low pressure because of its thinner atmosphere